Add real logging support.
Fix the patch path mungling that was broken earlier.
Add and proper refactor automatic gclient and gcl settings detection.
Factored so it is possible to add other autodetection algorithms.
Now works standalone in hybrid svn&git checkouts within a gclient meta-checkout.

TEST=bah
BUG=none
TBR=bradnelson

Review URL: http://codereview.chromium.org/517005

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@35218 0039d316-1c4b-4281-b951-d872f2087c98