Merged in chrishamm's changes to Network, PrintMonitor, and his support
for firmware updates from SD card
Fixed print monitor issue that threw out the layer count and time
estimates when there was an initial extruder priming move in the start
gcode
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)