fixed: We can't grab the duration from the streamdetails for stacks
[GLES] Fix for SBS rendering and cached viewport

I've also changed the unused function CLinuxRendererGLES::RenderMultiPass
to use the caching wrapper for SetViewPort.
Makes no odds now, but may avoid a problem if it's enabled in future.
[fix] Could not edit/assign movie to movie set after #3642
due to https://github.com/Montellese/xbmc/commit/e14fae38dec48cd1cd36f875f1ebde5396f43d57
Merge pull request #3767 from Voyager1/fixmovieset

[fix] Could not edit/assign movie to movie set after #3642
[ios/atv2] - readd gitrev-posix which was wrongly removed in 05274bfcbcbbc96a5ee5a61bf4018b30719727f4 - its still needed in ios/atv2 packaging if we want to retain dsym files (on jenkins...)
Add missing includes of "system.h", fixes #14732
Merge pull request #3754 from popcornmix/fix_viewport_cache

[GLES] Fix for SBS rendering and cached viewport
[nfs] - get rid of some CStdStrings in favour of std::string
[nfs] - better fix for fe97d68f87d6985b2bf57d8e942b36b5e7373066 - possibly fixes #14727 - thx jm for the idea :)
Merge pull request #3699 from arnova/streamdetail_stack_time_fix

fixed: We can't grab the duration from the streamdetails for stacks