Adds a VideoToolbox based H264 encoder for OSX, which most notably
allows the use of hardware encoding (Quicksync).
NOTES:
- Hardware encoding is handled by Apple itself internally. The plugin
itself has little control over many details due to the way that Apple
designed the VideoToolbox interface. Generally however, quicksync is
used if available on the CPU, and quicksync is almost always available
due to the fact that macs are exclusively Intel.
- The VideoToolbox does not seem to implement CBR, so it won't be
available. These encoders are generally not recommended for
streaming.
