OpenSSL, Opus and x264 updates

The OpenSSL library was updated to 1.1.0f while Opus got a minor bug fix update to version 1.15. X264 was also updated to the latest stable r2768. 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.