Replaced cm9_bc_example with three somewhat comprehensive tutorials for usage of CM9_BC with poses, sequences, and RPM_arrays.
Also fixed playing() and interpolating() so that they actually can control the playing state.
argh. finished modifying files while writing last commit message.
Hopefully the new comments in CM9_BC.h will actually produce the correct output, but have not tested that or the tutorial examples.  Ran out of time before class, so will test this evening.
Few small fixes, but everything should work fine now.  The tutorials show how to use each layer of the motion engine (poses with manual interpolation, sequences with automatic pose changes, and RPM 'pages' with automatic progression to 'next' and 'stop' pages).
Need to make some modifications to PyPose (python script) to make it output header files compatible with the CM9_BC, and add a small delay to the execute() function in driver.py to ensure it waits long enough for the CM9 to build and send a reply packet.
The arbotix has no problem because it requires an FT232RL which has a minimum timeout period after receiving data on its UART to the time it sends a packet on USB.  The CM9 has hardware USB which can be polled by the PC immediately for available data and will often not yet have any of the response data in the output USB buffer when polled by PyPose.