redo the background discovery method in end_station_imp.cpp
apply astyle
Remove (c) AudioScience, Inc output on startup of cmdlineapp.
cmdlineapp: use enum for log level
controller: lib: background read of descriptors update

Timeout is increased from 250ms to 750ms
Background reads can now timeout without requiring receipt of an incoming packet.
linux build fix
Merge pull request #114 from andrew-elder/staging

backbround descriptor read update