- Python2.7.5 will be installed only if DEPOT_TOOLS_PYTHON_275=1,
  otherwise 2.6 is installed.
- Eventually the default will be changed to install python 2.7.5
  for new users.
- Afterward, python 2.7.5 will be always installed when not detected
  and 2.6 will be ignored.

README.chromium contains the exact instructions how to recreate
python275_bin.zip that was committed independently.

I tested it on a vanilla Windows XP image and documented how to
install the VC90 CRT redistributable in that specific case in
README.chromium.

R=iannucci@chromium.org
BUG=241769,257696

Review URL: https://codereview.chromium.org/26326002

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@227961 0039d316-1c4b-4281-b951-d872f2087c98