Various minor settings level adjustments to settings.xml

As discussed on the internal Team XBMC forum thread here: http://forum.xbmc.org/showthread.php?tid=163982

Various non-controversal level adjustments for various settings.
videoplayer.useframemtdec 2 -> 3

change level of videoplayer.useframemtdec (Frame Multi Thread Decoding) as requested by fritsch
[PVR] updated settings levels
Merge branch 'nedsettings'