cleanup: Auto-format some xml files (no functional changes).
front: Move Audio settings to Advanced menu.
front: Remove Plug-ins menu, move items to other menus.

Video plug-in -> Video menu
R4300 emulator -> Advanced menu
front: Stay in video menu when video plugin changes.
front: Assume we always have vibrate permission.

We added these tests in case we needed to yank vibrate permission from
the OUYA build.  Since we learned we don't, then it's fine to remove
these checks.
jni/front: Remove isRGBA8888 method/option.
front: Re-order video menu.
front: Disable audio prefs if audio disabled.
input: Multi-mapping only allowed if all inputs are digital.

Note that this doesn't alter anyone's existing settings or custom pro-
files.  It only addresses new users and new custom mappings by exist-
ing users.

Addresses problem described here:
http://www.paulscode.com/forum/index.php?topic=1181.msg11095#msg11095
http://www.paulscode.com/forum/index.php?topic=1272.msg11462#msg11462