Igcs 121 fwr firmware loader

- Prompt user to update FWR accessory firmware when there is
  and newer version in the app bundle.

- In DEBUG builds there is an "Update Firmware" button
  in the radio config screen to help us test and revert to older
  firmware manually if needed. Possible to move to DEBUG screen.

- Rename FirmwareUploader to SiKFirmwareUploader since
  we will two separate firmware programs to update.

- Add `/scripts/updatedepends.sh` to update submodules
  and pull down any private dependencies needed for
  app store submission/ad-hoc builds. 

- Add Run Script build phase to copy dependencies
  to bundle if any exist.

- A bit of cleanup in FightingWalrusInterface

- Updated README
@cnatoli 
With your proposed method I get back: (UInt8) digest2 = '\xbc'

While with my method I get back the expected result represented as "Z\xe4\xbe\x80\xe4k\xd9'0;#" for walrus.bin v0.0.5

What am I missing?