smaccmpilot: Add I2C and EEPROM modules.
smaccmpilot: Initial parameter implementation.

- Added Ivory C string utility module.
- Added SMACCMPilot.Param module to track run-time parameters.
- Moved definition of stabilzer PIDs into Ivory.
- Added parameters for stabilizer PID gains.
smaccmpilot: First attempt at MAVlink parameters.

- Reading single parameter values is working.
- The MAVlink module may need some redesigning to support sending
  responses from the "gcs_receive" module.
smaccmpilot: Tidy up names of param functions.

- Prefix everything with "param_" for namespacing.
smaccmpilot: Clean up parameter request interface.

- Fix loop bugs in Ivory code.
- The GCS receive task now marks parameters for transmission.
- Added a timed action to the GCS transmit task to find a marked
  parameter and send it via MAVlink.
- MAVProxy now correctly fetches all parameters on startup.
smaccmpilot: Implement setting parameters via MAVlink.
smaccmpilot: Update to new Ivory Ix and loop functions.
smaccmpilot: Add partition module.