[IMP] firmware: Break out UI handlers * Create UI handlers that will implement different UIs (BMBT vs CD53) * Improve the way that messages are displayed on the CD53 * Add handling of Ignition Status (Close all connections on ignition off) * Add code to disconnect devices that are not the active media player * Automatically select the playing device as the active media player * Begin building BMBT handler

[IMP] firmware: Multiple enhancements to IBus Module * Enhance Display Text code -- Use strncpy instead of a loop * Read IBus RX line status to determine ability to send * Add ability to send symbols to the MID * Remove char queue capacity field, since it is never used externally. * Increase timer ISR priority to 2 * Improve UART ISR functions & Set the UART registers as volatile * Enable code optimization to level 1

[IMP] firmware: Bugfixes & Melody 7 support * Improve IBus contention code -- No FERR/PERR errors now, even when spamming the bus * Refactor BC127 implementation to support Melody 7 * Improve code surrounding BC127 Metadata parsing * Improvements to Pairing mode * Improvement to UART state tracking. New code sets the receive state and then leaves it to the implementation to reset the module to idle. We can use the protocol to define when the full message has been received, or if it is garbage.

[IMP] firmware: Improvements to further prevent FERR/PERR on IBus * Improve complexity of UART modules * Couple of changes to support Melody 7.1

[FIX] firmware: Fix several bugs causing IBus contention * Add additional debugging across firmware * Add uptime in millis to debug messages * Add status tracking to UART modules * Fix issues causing IBus contention by manually pushing bytes to TX register, thus avoiding the extra overhead of the TX ISR. * Fix Char Queue typedefs (uint8_t instead of int16_t) * Increase metadata field size for BT module * Spacing fixes for Traps

[FIX] firmware: Resolve IBus Frame errors * Resolve bug where the IBus would puke random frame errors by not transmitting while the RX buffer has data in it, which is essentially "mid-reception" * Additional logging * Improve ISR Flag triggers

[IMP] firmware: Many bugfixes and improvements to the IBus handling code * Add XOR checksum verification of IBus messages * Abstract BT connections * Add debugging for frame/pairity errors on UART * Adjust code to allow differing TX / RX IPs * Remove debugging from Char Queue and lower size to decrease stack size

[IMP] firmware: Enhance BT / IBus connectivity * Pause / Request data based on state changes * Remove useless "struct" declarations * Resolve bug with scheduled tasks * Use pointers instead of copying objects in several places

[IMP] firmware: Switch to event driven architecture * Add TimerSchedule that runs tasks at given intervals * Improve CD Changer Emulation * Remove lots of hardcoded values * Add Debugging to check for largest values in Char Queue

[IMP] firmware: Improve IBus text display & Begin Event typing