Switched to the new build system that doesn't need the Eclipse Arduino
plugin and uses the CoreDuet project instead of Arduino to provide
hardware support
Enabled gcc compiler warnings. Fixed over 100 warnings including at
least one actual and several potential bugs.
Simplified delta calibration code and added X and Y parameters to M665
command
Implemented chamber temperature commands (thanks chrishamm)
Tidied up delta auto-calibration code. We now use least squares for 3,
4, 6 or 7-factor calibration.
When doing delta calibration, if a probe offset was used to adjust the
head position when probing, use the actual head coordinates instead the
probed coordinates.
Bug fix: newline was missing at end of SD card file list sent to USB
when in Marlin emulation mode.
Bug fix: Heater average PWM report (M573) sometimes gave inaccurate
values when the S parameter was used.
