Added gaussian noise function.  Currently noise will not be added to measurements unless a user changes the initialization value and builds from source.

Added setter functions for HIL noise variances.  Researching methods to add zero mean gaussian random number before implementation

Also:
- Prompts to reset trims to zero prior to calibrate
- Turned of radio check for now since it prevents spectrum bind

- Download working again
- Fixed lots of bad error handling

writeFileAccumulator contents cleared on errors, nack or ack timeout
memcpy used to transfer data to request message buffer

QGCUASParamManager and friends are replaced by FactSystem