contributing: Transition from GitHub's wiki format to pure Markdown
CONTRIBUTING.md: Start listing maintainers

Also suggest using commit message and pull request summary prefixes,
along the lines of those used by the Linux and Git projects.

Maintainers should link to their GitHub profile, and I've used a blank
line to separate these maintainer links from the other links used in
the text.  Alphabetical order would be nice, but it doesn't really
matter ;).
Merge branch 'wiki' into restructured
CONTRIBUTING.md: Link to the contributing/ docs

This probably should have happened when they were still stand-alone
wiki pages, but it should definitely happen now that they are in-tree.
Merge branch 'restructured-version-control' into restructured

* restructured-version-control:
  version-control/git/README.md: Add paragraph pitching Git
  version-control/README.md: Add a motivational paragraph
  version-control/git: Use git-and-github notes
  version-control/svn/cheet-sheet.md: Add a Subversion-specific cheat sheet
  version-control/git/cheet-sheet.md: Add a Git-specific cheat sheet
  version-control/cheet-sheet.md: Add a generic outline for the cheat sheet
  version-control: Make README.md and instructor.md more generic
  version-control: Add README.md and instructor.md from the guide
Merge branch 'restructured-testing-nose' into restructured

* restructured-testing-nose:
  testing: More restructuring for the Nose source
  testing/cheat-sheet.md: Split Nose-specific stuff into nose/cheat-sheet.md
  testing/nose: Restructure to split out examples
  testing/nose: Move example scripts into the examples/ subdirectory
  testing/nose: Move media into the media/ subdirectory
  testing/nose: Move existing Nose material to $SUBJECT/$TOOL