Packages the distutils stdlib module as a standalone package,
```
377K distutils.data
221K distutils.data.br
19K distutils.js
```
to reduce the minimal pyodide size.

Part of #1542 

This also,
 - adds documentation on what's supported or not in the stdlib
 - makes a few changes to `pyodide_build/buildall.py` to be able to add such stdlib packages as a dependency in other packages (which didn't work before). For instance, until there is a release with https://github.com/pypa/packaging/pull/396 micropip has a dependency on distutils.
Unvendor distutils. Packages the distutils stdlib module as a standalone package,
```
377K distutils.data
221K distutils.data.br
19K distutils.js
```
to reduce the minimal pyodide size.

Part of #1542 

This also,
 - adds documentation on what's supported or not in the stdlib
 - makes a few changes to `pyodide_build/buildall.py` to be able to add such stdlib packages as a dependency in other packages (which didn't work before). For instance, until there is a release with https://github.com/pypa/packaging/pull/396 micropip has a dependency on distutils.
package:
  name: nlopt
  version: 2.7.0

source:
  url: https://github.com/stevengj/nlopt/archive/v2.7.0.tar.gz
  sha256: b881cc2a5face5139f1c5a30caf26b7d3cb43d69d5e423c9d78392f99844499f

  extras:
    -
      - src/setup.py
      - ./setup.py

requirements:
  run:
    - numpy

build:
  cxxflags: -std=c++11

test:
  imports:
    - nlopt

package:
  name: nlopt
  version: 2.7.0

source:
  url: https://github.com/stevengj/nlopt/archive/v2.7.0.tar.gz
  sha256: b881cc2a5face5139f1c5a30caf26b7d3cb43d69d5e423c9d78392f99844499f

  extras:
    -
      - src/setup.py
      - ./setup.py

requirements:
  run:
    - numpy

build:
  cxxflags: -std=c++11

test:
  imports:
    - nlopt
