bash completion: Sync config variables with their man pages
bash completion: Sync config variables with their man pages

Add 'normal' to config color options.
Add 'mergeoptions' to branch config options.
Add 'proxy' and 'mirror' to remote config options.

Signed-off-by: Lee Marlow <c895bdfdd1bf99084d7efdbd77c43126cd4b21a6@gmail.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