* FFmpeg4 support. Compile warnings fixes. Credit goes to many people, including ferdnyc, peterM, and other awesome folks!
* Adding environment checking to enable/disable omp taskwait after each video/audio frame is processed. This is experimental for some users with crashes.
* Moving `omp taskwait` to after the ProcessVideoPacket() method, since that is the only place it is useful.
* Fixing crashes on missing Clip source file, and changing FFmpeg scaling algorthm from SWS_BILINEAR to SWS_LANCZOS (for higher quality scaling)
* Update FindFFmpeg.cmake module, and updating build script. Also enabling debug builds.
* Updating experimental travis build script
* Fixed unit test for newer version of FFmpeg (audio resampling)
* Experimental travis multiple jobs
* Adding OMP schedule hint (thanks PeterM), which prevents crashes in some circumstances.
Also, much work has been done on memory management / leak detection, and optimizations with multi-threading... including a new thread cacher class used by the video playback (which is smoother than ever).
Better bounds checking, and support at the end of the video file
Improved debug output, which helped resolve many issues
Implemented the newest audio decoding API (old one was depreciated)
Now support packed and planar audio data
Far superier audio resampling support
