Process system updates:

All processes:
- Added process status system and relevant API calls
- Added ability to set track masks for input/output in processes
- Added support for unmasking tracks when there is a push target, by the "unmask" parameter.
- Added track unmasking support for processes on exit/error
- Make processes start faster, if possible, in the first few seconds of a stream
- Delay stream ready state if there are processes attempting to start

Livepeer process updates:
- Added Content-Resolution header to MistProcLivepeer as per Livepeer's request
- Renamed transcode from "Mist Transcode" to source stream name
- Added ability to send audio to livepeer
- Robustified livepeer timing code, shutdown code, and improved GUI
- Prevent "audio keyframes" from starting segments in MistProcLivepeer
- Multithreaded (2 upload threads) livepeer process
- Stricter downloader/uploader timeout behaviour
- Robustness improvements
- Fix small segment size 😒
- Streamname correction
- Prevent getting stuck when transcoding multiple qualities and they are not equal length
- Corrected log message print error
- Race condition fix
- Now always waits for at least 1 video track

lib/dtsc.cpp

@@ -24,6 +24,8 @@ namespace DTSC{
 
   /// The mask that the current process will use to check if a track is valid
   uint8_t trackValidMask = TRACK_VALID_ALL;
+  /// The mask that will be set by the current process for new tracks
+  uint8_t trackValidDefault = TRACK_VALID_ALL;
 
   /// Default constructor for packets - sets a null pointer and invalid packet.
   Packet::Packet(){
@@ -1701,7 +1703,7 @@ namespace DTSC{
     trackList.setInt(trackPidField, getpid(), tNumber);
     trackList.setInt(trackSourceTidField, INVALID_TRACK_ID, tNumber);
     trackList.addRecords(1);
-    if (setValid){validateTrack(tNumber);}
+    if (setValid){validateTrack(tNumber, trackValidDefault);}
     if (!isMemBuf){trackLock.post();}
     return tNumber;
   }