Import r1244 from kex

r1244 | svkaiser | 2013-12-29 18:12:12 -0800 (Sun, 29 Dec 2013)
+ Attempt to fix audio de-syncs with some music data
+ Fixed bug where automap inputs would not eat the input events while
shooting in automap panning mode
+ Allowing the ability to take screenshots while menus are active
+ Force-clear all mobj sources in audio channels
Import r1246, freelook option for MAPINFO