Refactored temperatyure sensor code
Refactored fan control code
Support invisible axes (M584 P parameter)
Supprt user-defined virtual heaters
Support heater names
Support proportional thermostatic fan control
Fix G10 retraction command
Removed delta probe code
Fixed CoreXY motor factor initialisation
Fixed mesh bed levelling
Fixed driver temperature thermostatic fan control
Suppress driver temperature warnings when an associated thermostatic has
just kicked in
Improved reliability of new interface to WiFi module
Added options to control thermostatic fans based on CPU and driver
temperatures
Support M204 S parameter for backwards compatibility
Fixes to Scara kinematics
Support additional axes on delta printers
Added extra info to M122 repoirt
