remote: add 'rm' subcommand
remote: add 'rm' subcommand

Introduce git-remote rm <name> which will:
 - Remove the remote config entry for <name>.
 - Remove any config entries for tracking branches of <name>.
 - Remove any stored remote branches of <name>.

Signed-off-by: James Bowes <366c30c9a12672a1ada45eb161d9344bb0512b1b@dangerouslyinc.com>
Signed-off-by: Junio C Hamano <a6723cc3f76163bf7adb636a73ac3b0ceb3e6b9b@pobox.com>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git