1. Moved plotStickPositions() function to RateCurve.js and renamed to
drawStickPositions()
2. Modified currentValue to prevent 0/-0 flickering.
3. Layers given unique id’s to remove indexing.
4. RC value monitoring now in function TABS.pid_tuning.checkRC()
5. updateRateLabels now in function TABS.pid_tuning.updateRateLabels()
6. Moved drawAxisLabel() and drawBaloonLabel() into function
TABS.pid_tuning.updateRateLabels() (as they are only used there)