Data stream manager concept

[dtmoodie]

Generally each video stream will have a separate processing tree. Interaction could occur between trees for things like stereo vision.
The top level node in a processing tree should create a data stream manager. This stream manager will act like the system table in that it will have pointers to all the interfaces for this stream.
Some examples of these interfaces.

• User interface callbacks
• Coordinate system conversions.
  -- Image space, world space, camera space, render space, etc.
• Drawing to the render window

This would help segregate the events and signals of a specific stream. The old event / callback system should stay in place for global information. But all the data stream specific stuff should be routed through the data stream manager