Add support for swarm seccomp and apparmor
**- What I did**

Added support in Swarm for custom Seccomp profiles, some small amount of AppArmor configuration, and `no-new-privileges`.

**- How I did it**

Swarmkit has the necessary plumbing for these fields added, and now it's wired up in the engine.

**- How to verify it**

**- Description for the changelog**
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Write a short (one line) summary that describes the changes in this
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Added Swarm support for seccomp, AppArmor, and no-new-privileges.

api/types/swarm/container.go
package swarm // import "github.com/docker/docker/api/types/swarm"

import (
	"time"

	"github.com/docker/docker/api/types/container"
	"github.com/docker/docker/api/types/mount"
	"github.com/docker/go-units"
)

// DNSConfig specifies DNS related configurations in resolver configuration file (resolv.conf)
// Detailed documentation is available in:
// http://man7.org/linux/man-pages/man5/resolv.conf.5.html
// `nameserver`, `search`, `options` have been supported.
// TODO: `domain` is not supported yet.
type DNSConfig struct {
	// Nameservers specifies the IP addresses of the name servers
	Nameservers []string `json:",omitempty"`
	// Search specifies the search list for host-name lookup
	Search []string `json:",omitempty"`
	// Options allows certain internal resolver variables to be modified
	Options []string `json:",omitempty"`
}

// SELinuxContext contains the SELinux labels of the container.
type SELinuxContext struct {
	Disable bool

	User  string
	Role  string
	Type  string
	Level string
}

// CredentialSpec for managed service account (Windows only)
type CredentialSpec struct {
	Config   string
	File     string
	Registry string
}

// Privileges defines the security options for the container.
type Privileges struct {
	CredentialSpec *CredentialSpec
	SELinuxContext *SELinuxContext
}

// ContainerSpec represents the spec of a container.
type ContainerSpec struct {
	Image           string                  `json:",omitempty"`
	Labels          map[string]string       `json:",omitempty"`
	Command         []string                `json:",omitempty"`
	Args            []string                `json:",omitempty"`
	Hostname        string                  `json:",omitempty"`
	Env             []string                `json:",omitempty"`
	Dir             string                  `json:",omitempty"`
	User            string                  `json:",omitempty"`
	Groups          []string                `json:",omitempty"`
	Privileges      *Privileges             `json:",omitempty"`
	Init            *bool                   `json:",omitempty"`
	StopSignal      string                  `json:",omitempty"`
	TTY             bool                    `json:",omitempty"`
	OpenStdin       bool                    `json:",omitempty"`
	ReadOnly        bool                    `json:",omitempty"`
	Mounts          []mount.Mount           `json:",omitempty"`
	StopGracePeriod *time.Duration          `json:",omitempty"`
	Healthcheck     *container.HealthConfig `json:",omitempty"`
	// The format of extra hosts on swarmkit is specified in:
	// http://man7.org/linux/man-pages/man5/hosts.5.html
	//    IP_address canonical_hostname [aliases...]
	Hosts          []string            `json:",omitempty"`
	DNSConfig      *DNSConfig          `json:",omitempty"`
	Secrets        []*SecretReference  `json:",omitempty"`
	Configs        []*ConfigReference  `json:",omitempty"`
	Isolation      container.Isolation `json:",omitempty"`
	Sysctls        map[string]string   `json:",omitempty"`
	CapabilityAdd  []string            `json:",omitempty"`
	CapabilityDrop []string            `json:",omitempty"`
	Ulimits        []*units.Ulimit     `json:",omitempty"`
}

package swarm // import "github.com/docker/docker/api/types/swarm"

import (
	"time"

	"github.com/docker/docker/api/types/container"
	"github.com/docker/docker/api/types/mount"
	"github.com/docker/go-units"
)

// DNSConfig specifies DNS related configurations in resolver configuration file (resolv.conf)
// Detailed documentation is available in:
// http://man7.org/linux/man-pages/man5/resolv.conf.5.html
// `nameserver`, `search`, `options` have been supported.
// TODO: `domain` is not supported yet.
type DNSConfig struct {
	// Nameservers specifies the IP addresses of the name servers
	Nameservers []string `json:",omitempty"`
	// Search specifies the search list for host-name lookup
	Search []string `json:",omitempty"`
	// Options allows certain internal resolver variables to be modified
	Options []string `json:",omitempty"`
}

// SELinuxContext contains the SELinux labels of the container.
type SELinuxContext struct {
	Disable bool

	User  string
	Role  string
	Type  string
	Level string
}

// SeccompMode is the type used for the enumeration of possible seccomp modes
// in SeccompOpts
type SeccompMode string

const (
	SeccompModeDefault    SeccompMode = "default"
	SeccompModeUnconfined SeccompMode = "unconfined"
	SeccompModeCustom     SeccompMode = "custom"
)

// SeccompOpts defines the options for configuring seccomp on a swarm-managed
// container.
type SeccompOpts struct {
	// Mode is the SeccompMode used for the container.
	Mode SeccompMode `json:",omitempty"`
	// Profile is the custom seccomp profile as a json object to be used with
	// the container. Mode should be set to SeccompModeCustom when using a
	// custom profile in this manner.
	Profile []byte `json:",omitempty"`
}

// AppArmorMode is type used for the enumeration of possible AppArmor modes in
// AppArmorOpts
type AppArmorMode string

const (
	AppArmorModeDefault  AppArmorMode = "default"
	AppArmorModeDisabled AppArmorMode = "disabled"
)

// AppArmorOpts defines the options for configuring AppArmor on a swarm-managed
// container.  Currently, custom AppArmor profiles are not supported.
type AppArmorOpts struct {
	Mode AppArmorMode `json:",omitempty"`
}

// CredentialSpec for managed service account (Windows only)
type CredentialSpec struct {
	Config   string
	File     string
	Registry string
}

// Privileges defines the security options for the container.
type Privileges struct {
	CredentialSpec  *CredentialSpec
	SELinuxContext  *SELinuxContext
	Seccomp         *SeccompOpts  `json:",omitempty"`
	AppArmor        *AppArmorOpts `json:",omitempty"`
	NoNewPrivileges bool
}

// ContainerSpec represents the spec of a container.
type ContainerSpec struct {
	Image           string                  `json:",omitempty"`
	Labels          map[string]string       `json:",omitempty"`
	Command         []string                `json:",omitempty"`
	Args            []string                `json:",omitempty"`
	Hostname        string                  `json:",omitempty"`
	Env             []string                `json:",omitempty"`
	Dir             string                  `json:",omitempty"`
	User            string                  `json:",omitempty"`
	Groups          []string                `json:",omitempty"`
	Privileges      *Privileges             `json:",omitempty"`
	Init            *bool                   `json:",omitempty"`
	StopSignal      string                  `json:",omitempty"`
	TTY             bool                    `json:",omitempty"`
	OpenStdin       bool                    `json:",omitempty"`
	ReadOnly        bool                    `json:",omitempty"`
	Mounts          []mount.Mount           `json:",omitempty"`
	StopGracePeriod *time.Duration          `json:",omitempty"`
	Healthcheck     *container.HealthConfig `json:",omitempty"`
	// The format of extra hosts on swarmkit is specified in:
	// http://man7.org/linux/man-pages/man5/hosts.5.html
	//    IP_address canonical_hostname [aliases...]
	Hosts          []string            `json:",omitempty"`
	DNSConfig      *DNSConfig          `json:",omitempty"`
	Secrets        []*SecretReference  `json:",omitempty"`
	Configs        []*ConfigReference  `json:",omitempty"`
	Isolation      container.Isolation `json:",omitempty"`
	Sysctls        map[string]string   `json:",omitempty"`
	CapabilityAdd  []string            `json:",omitempty"`
	CapabilityDrop []string            `json:",omitempty"`
	Ulimits        []*units.Ulimit     `json:",omitempty"`
}

Do we want these to have an `omitempty` ?  (also for older API versions?)