git_config: add support for remote '.'

As a fix for issue #149, this patch add support for the remote '.'
(local).

As an alias for the local repository, remote '.' is lacking a fetch =
config in .git/config.

Without such refspec, repo info --overview is not able to process a
local tracking branch.

v2: Check for name == '.' before checking if merge starts with refs/,
    since the case where it's not is invalid.

Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
Signed-off-by: Filipe Brandenburger <filbranden@google.com>

Change-Id: I8c8fd8602cd68baecb530301ae41d37d751ec85d
1 file changed