FFVS Project Generator and Opus, libmfx, Gcrypt, x264 updates

The Opus library was updated to 1.2.1, libmfx was updated to support the latest 1.23 intel qsv api, gcrypt was updated to 1.7.8 and x264 was updated to r2795. The FFVS Project Generator also had a bump to version 1.5.3. As always the latest releases are available on the Projects page while still allowing access to any previously supported releases. The latest FFmpeg build has also been updated to use the latest versions of the new libraries as well.