Give the AppendDebugMethod() declaration a set of default values for
all parameters after the first. (It uses `""` and `-1.0`, which are
what callers were passing in anyway.) This way, callers have the
_option_ to eschew this kind of thing:
```
ZmqLogger::Instance()->AppendDebugMethod("Message", "start", start,
"length", length, "", -1, "", -1, "", -1, "", -1);
```
instead, they can use the functionally equivalent:
```
ZmqLogger::Instance()->AppendDebugMethod("Message", "start", start,
"length", length);
```
Passing meaningless args is the compiler's job, not the programmer's.
* 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.