Renamed documentation files to .txt and converted them to DOS line endings so they would open properly on all systems.
Updated Makefile.in so "make dist" includes everything necessary for release.

--HG--
rename : BUGS => BUGS.txt
rename : COPYING => COPYING.txt
rename : CREDITS => CREDITS.txt
rename : INSTALL => INSTALL.txt
rename : README.android => README-android.txt
rename : README.cmake => README-cmake.txt
rename : README.DirectFB => README-directfb.txt
rename : README.gesture => README-gesture.txt
rename : README.HG => README-hg.txt
rename : README.iOS => README-ios.txt
rename : README.MacOSX => README-macosx.txt
rename : README.pandora => README-pandora.txt
rename : README.Platforms => README-platforms.txt
rename : README.Porting => README-porting.txt
rename : README.psp => README-psp.txt
rename : README.touch => README-touch.txt
rename : README.WinCE => README-wince.txt
rename : README => README.txt
rename : TODO => TODO.txt
Fixed compile errors building with mingw64
Don't assume the XAudio2 APIs will never be available