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.
Added almost instant pause functonality
Support pause and resume macros
Support nested macros
Support zpl's web interface
Merge in zpl's web interface and network changes
Add R parameter to M105 command for PanelDue
M98 can now run macros from any SD card folder
Fixed bug: if 5 point bed compansation was used then doing G32 more than
once would try to move the head off the edge of the bed unless the first
4 probe coordinates were reset between them.
Fixed bug: if the last command in a a macro file did not end in newline
then it might not be fully executed
Bug fix: potential array underrun in Gcodes::Pop()
Reduced Z dive height back to 5mm
