OpenRTX v0.3.3

Experimental support for M17 digital radio protocol, with thanks to Wojciech Kaczmarski SP5WWP and all the community.

• Functional TX and RX of audio on MD-3x0 UHF devices.
• Functional RX of audio on MD-3x0 VHF devices.
• Functional TX and RX of audio on MD-UV3x0 devices.

Support for a new target, Module 17, thanks to Mathis Schmieder DB9MAT.

Persistence of user settings at power-off on MD-3x0 and MD-UV3x0.

Build file and code adaptations to allow compilation and running of the emulator under Mac OS X, thanks to Alessio Caiazza IU5BON.

Automatic screen power-off with user-configurable timeout, thanks to Alessio Caiazza IU5BON.

Menu entry allowing to reset user settings to their default state, thanks to Mike McGinty W2FBI.

Experimental backup and restore of external flash via xmodem on MD-3x0 and MD-UV3x0.

Various bug fixes and improvements.