Also add git-crsync as shorthand for `git crup --sync`.

TBR=iannucci@chromium.org

BUG=

Review URL: https://codereview.chromium.org/12279006

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@182767 0039d316-1c4b-4281-b951-d872f2087c98