call into a new UORB COMMUNICATOR ICHANNEL shutdown interface if it has been configured, otherwise it
does nothing. This allows ICHANNEL implementations to pass on a shutdown indication to a remote processor.
Implemented the shutdown interface in the muorb module for VOXL flight controllers.
* Removed exit after dsp signature generation.
* First full test suite
* Cleaned up the muorb tests
* Improved VOXL 2 self test trigger in startup file
* Removed unneeded include file
Eric Katzfey