* Spelling fix, changing to stop_function_t from stop_funtion_t.
 * Corrected the timed circular buffer get to timeout.

Move all the trender threads to being tracked by a thread handler and having a uniform stop signal.

Add a timed_get function to the circular buffer which will allow queries to the circualr buffers to time out.  This is used to allow the trender to see a stop request.

This is done as part of expanding the wrapping of the pthread... calls with C++.  Starting on a interface to better track threads.