Git configuration.
- Don't ignore all files, but set status.showUntrackedFiles to no, add
to post-merge hook.

squashes and merges).
- Modify fixup and add squash Git aliases to be fully automated (no need
to enter the commit intended).

- Correct bug when running git update-requirements when there are more than 2 requirements files in the repo.

- Added update-requirements Git alias (same as the update-requirements shell alias but also commits the changed files.)

- Added autosquash Git alias.

- Reordered entries alphabetically.

- Added git serve-http alias (serve over HTTP on port 8000 with Python's
  SimpleHTTPServer module).

- Added git serve alias.