Add git:// and mms:// to $wgUrlProtocols

Add git:// and mms:// to $wgUrlProtocols

git:// seems like a no-brainer, since we support svn://.  mms:// was
originally a proprietary Microsoft protocol, but they released a spec
and there are multiple open-source implementations, so why not.  Someone
requested the latter on [[WP:VPT]]:

<http://en.wikipedia.org/w/index.php?title=Wikipedia:Village_pump_(technical)&diff=351780595&oldid=351776934>

No reason to be stingy about adding $wgUrlProtocols default values, if
they don't take scary actions when clicked, right?