git-credential-luci: Make it work, add some bells and whistles.
git-credential-luci: Make it work, add some bells and whistles.

In particular:
  * Use 'git-<something>' as username, Gerrit doesn't like 'o' here.
  * Add 'luci-git-user' subcommand that returns an email and a user name that
    matches the credentials used. Useful when pushing commits to Gerrit.

R=28e431f5669ee416eed3c0cf0e57e28af39903b5@chromium.org
BUG=756224

Change-Id: I0017d2b9e3855b60134c7a71736f3d7438076b32
Reviewed-on: https://chromium-review.googlesource.com/648344
Reviewed-by: Petr Hosek <28e431f5669ee416eed3c0cf0e57e28af39903b5@chromium.org>
Commit-Queue: Vadim Shtayura <9f116ddb1b24f6fc1916a676eb17161b6c07dfc1@chromium.org>

luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go