commands.go
func NewLongThen(command string, args ...string) Then {
	return &gitCmd{command: command, args: args, background: true, haltChan: make(chan struct{})}
}
func NewLongThen(command string, args ...string) Then {
	return &gitCmd{command: command, args: args, background: true, haltChan: make(chan struct{})}
}
// NewLongThen creates a new long running Then comand.