Access git repositories through stable url's that don't require .git appended

Specifically, you cannot checkout from https://git.chromium.org/chromiumos/manifest,
only https://git.chromium.org/chromiumos/manifest.git.  Using the new /git/ prefix,
manifest or manifest.git can be used.  This matches git:// behaviour, and works around
repo dropping the auto-appending of .git in >=1.7.7.5

Note that this is attempt #2 to land this; outstanding blockers should now be
fixed.  Original attempt: I63ab9e5acfd402c12e31ac13cf70a30320c9d11e

BUG=chromium-os:24413, chromium:108196
TEST=repo sync
CQ-DEPEND=I63ab9e5acfd402c12e31ac13cf70a30320c9d11e

Change-Id: Ie573641fdff4acb4267d2bfbe499fcbfb0a2b7db
Reviewed-on: https://gerrit.chromium.org/gerrit/13395
Reviewed-by: Chase Phillips <cmp@chromium.org>
Tested-by: Brian Harring <ferringb@chromium.org>
Reviewed-by: Ryan Cui <rcui@chromium.org>
Commit-Ready: Brian Harring <ferringb@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/13595
Reviewed-by: David James <davidjames@chromium.org>
Tested-by: David James <davidjames@chromium.org>
2 files changed