Radio config checkpoint
Little (probably incorrect) fsm for parsing AT commands
Fill out iGCSRadioConfig class to gather params

- Added methods to gather just about all
  settings from an attached radio. Commands
  are sent one at a time. No support for
  retry yet.
Prefix for pop array category
iGCSRadioConfig header defs
Simplify GCSSikAT by providing AT/RT constants seperatly

- Add GCSRadioSettings model object
- updateModelWithKey:andValue method
- update each model property as it comes
  in from the radio
Ensure KVO messages get sent for radioSettingsModel

- use setters on radioSettingsModel
- rename iGCSRadioConfig timer responsible
  for AT command timeouts
- Update GCSRadioSettings description method
- implement observeValueForKeyPath:ofObject:change:context
  to observe GCSRadioSettings model and update UI.
Don't rely on timers to dispatch AT commands

- Remove _queueTimer
- dispatch a new AT command off queue once
  we have a response from previous command.
Another radio config checkpoint
Basic remote radio detection
Now the apps responsibility to enable config mode for radio chip

- Opening com.fightingwalrus.config accessory protocol no longer
  enables AT mode on radio chip due to timing issue since radio
  goes into low power whenever EAAccessory connection is torn down.
  The current solution is reset any EAAccessory connection and bring
  up a new connection using the com.fightingwalrus.config protocol to
  disable any com.fightingwalrus.telemetry or other protocol specific
  handling on the device, wait a second or two for the radio to boot.
  Then send "+++" to put the SoC radio into AT mode. Once an OK comes
  back normal AT radio config commands can be sent.
use private properties in class extensions
Read local settings once we are in AT command mode
Checkpoint on firmware debug
Terminate AT commands with \r
More radio debugging
First pass at AT command retry support
Better handling of missing echos

- Rename state machine states for clarity
Add gcs_popFirst for use with Queues
rename gcs_popFirst to gcs_shift