Rename time fields to what they actually are with units.
Implement Talk Send and standardize on milliseconds for time fields in API:

- Uptime in audio data and video data are represented in 10ms in the
  datastream, while talk data is represented in 1ms.  Always use
  milliseconds in the API and convert automatially to/from datastream.
- Timestamps are represented in seconds in the datastream.  Always
  use milliseconds in the API and convert automatically to seconds
  in the datastream.