Made the menu icon on OS X grayscale to fit with most other programs (thanks, Kefran!)

From https://github.com/UniversalMediaServer/UniversalMediaServer/commit/c671173bc48c19757b3d9ce7adee3de3196a7910
Speedup file list population

From:
https://github.com/UniversalMediaServer/UniversalMediaServer/commit/6ccd72bb4abf183a88cc28ab3d890c2936c587d3
https://github.com/UniversalMediaServer/UniversalMediaServer/commit/c4e5eb12c94cab87fcadfb1d3b1426533ca5fedf
https://github.com/UniversalMediaServer/UniversalMediaServer/commit/101402a0fb0dcab7bd8bea3f7042f15836df4790
Updated deprecated FFmpeg syntax
Prevent logspam

From https://github.com/UniversalMediaServer/UniversalMediaServer/commit/fb12e4cad36313776609bb0736b3adecc43b9777
Allow users to specify renderer configurations they want to ignore

This is to make it easier for users to resolve renderer conflicts

Based on https://github.com/UniversalMediaServer/UniversalMediaServer/commit/f673ea0a89f53276d65024de196ab469700ea0df
Improved/fixed descriptions

From https://github.com/UniversalMediaServer/UniversalMediaServer/commit/2be99ae7966fab9942909d44556617031450eb43
Language updates

From https://github.com/UniversalMediaServer/UniversalMediaServer/commit/1b6c53a304f039b0b55ba41283e4ebe20d61c6cf
Compatibility fixes for Bravia TVs (big thanks to Serenus for lots of testing!)

Based on https://github.com/UniversalMediaServer/UniversalMediaServer/commit/2364554d1be60ea202f7a5818a7c16243bdb78fc
Streamlined isMuxable()

From https://github.com/UniversalMediaServer/UniversalMediaServer/commit/1eb6b73ddc4ecba30ca62086db7964a8078ff0f1
Language flags stuff

From:
https://github.com/UniversalMediaServer/UniversalMediaServer/commit/429c42d1b5d469216d4cf6d2f9e8a874d262863c
https://github.com/UniversalMediaServer/UniversalMediaServer/commit/e81950ff59d114139e24a514fe000cf8c69d7f59
Rollback 8a5ce2b
Bumped version to 2.6.4
Updated changelog
Official release of 2.6.4 for Windows and Linux
Merge branch '2.6.4' of github.com:UniversalMediaServer/UniversalMediaServer into OSX