CleanFlight on Linux using micro-controller for PWM/LCD

Finally have micro-controller sending PWM from a HK-T6A to Linux version of CleanFlight. 

Created a new protocol (protocolMsg), allowing to route messages between software components over UDP or within the app via message bus.

For example, CleanFlight has a PWM parallel RX IO software block and PWM RX driver block.  The PWM RX driver block was replaced with a PWM client protocolMsg handler, the micro-controller is a PWM server protocolMsg handler.  The messages are routed via UDP over USB.  

The goal is to update CleanFlight  CLI and msp to handle message processing from multiple transports, i.e. serial, UDP, TCP. 


CleanFlight Configurator is proper showing receiver status. USB/UDP is running at 28Kb/s for RPM messages.

To Do list:

• validate new Linux serial driver
• a simple libevent shim (same as UDP/TCP shim)
• used for GPS
•  validate new lcdStrip Shim
• allows routing LCD strip messages (LED RGB) to be routed to micro-controller.
• write dshot  shim
• allow sending sdhot motor messages to micro-controller