gcs recieve: factor DataRateMonitor into its own module
ivory-tower-aadl: give task and isr threads Priority attributes

* any user-defined task priority is higher than the default
  priority.
* all isr priorities are higher than any task priority
ivory-tower-frontend: omit aadl.debug, emit ivoryTypesDoc
flight: fix aadl build
tx messagedriver: bugfix for ATTITUDE message
joystick: initial readme.
gcs: deprecated script.
mavlink: bump submodule.
flight control: use same scale for throttle as rpy.
smaccm-mavlink & mavlink defs: add RADIO message (from apm)
gcs: add radio status packet output
gcs: remove dead code
gcs transmit driver for radio status
gcs transmit: refactor stream transmitters to use stack, not global state
commsec: add dependency at outermost tower layer

* using withModule inside Encrypt task duplicates dependency
flight params: refactored to have unique names per task

* caused naming collisions when instantiating gcsTower for
  two separate serial ports
* had to do some newtype rank-n trickery to satisify the type
  checker
gcs transmit: refactored and fixed bugs in GPS messages
smaccm-mavlink: recieve state type must be in its own module
commsec server: add command line options for serial port, server port
bump mavlink