gl: avoid grabbing viewport on each render

Same as 518556b45b61de06a0bc810147cd1a6347497461 but for GL
GL: switch to CPU based matrix caculations to match GLES

This drops use of glGet which causes a performance hit on some systems since
it forces a glFinish()
GL(ES): Simplify matrix stack handling
fixup! GL(ES): Simplify matrix stack handling
fixup! GL: switch to CPU based matrix caculations to match GLES
sorting: fix Container.SetSortMethod (fixes #15627)
FX: [jni] useExceptionCheck rather than ExceptionOccured

ExceptionOccured creates a local ref on a jthrowable that we leak.
FIX: [amc] check for exceptions on everything
Remove string initialization
cppcheck fixes in cores/dvdplayer/
Fixing vdp_st checking
Merge pull request #5999 from tobbi/cppcheck_perf_cores_dvdplayer
CHG: [droid] do not h/w decode SD video (save on support)
Merge pull request #6022 from koying/moreamcfixes
Merge pull request #5977 from Montellese/fix_container_setsortmethod_15627

sorting: fix Container.SetSortMethod (fixes #15627)
Merge pull request #6026 from tobbi/cppcheck_perf_android

Remove string initialization
Merge pull request #5775 from elupus/glgets

RFC: removal of glGet*
Merge pull request #4815 from koying/chgdroidnohwsd
Merge branch 'master' of https://github.com/xbmc/xbmc