Also fixes an msys (git-bash) incompatibility, similar to the one
fixed in crrev.com/4845f0ed694ff071da5f6ee937a0bce2ea4e6fd2.
This change doesn't actually use the wrapper in any new places, but
subsequent changes will be made to use it in places where
'exec python' is called directly, like gclient and fetch.
BUG=411518
R=iannucci@google.com
Review URL: https://codereview.chromium.org/1415993003
git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@297357 0039d316-1c4b-4281-b951-d872f2087c98
git-map: Show your local repo's history in a pseudo-graphical format from the command line.
git-map-branches: Show the topology of all of your branches, and their upstream relationships.
git-nav-upstream: Navigate (checkout) to the upstream branch of the current branch.
git-nav-downstream: Navigate (checkout) to a downstream branch of the current branch. If there's more than one downstream branch, then present a menu to select which one you want.
R=agable@chromium.org, hinoka@chromium.org, stip@chromium.org, szager@chromium.org
BUG=
Review URL: https://codereview.chromium.org/184113002
git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@256384 0039d316-1c4b-4281-b951-d872f2087c98