Version 0.78t

Bug fix: M92 command would only set extruder steps/mm if either 1 or 5
extruder steps/mm was provided
Bug fix: Z-homing or bed probing when axis compensation was enabled
caused the X and Y origins to shift
We now mark drives as not homed when we disable them
File info code now supports gcode files generated by Simplify3D
Updated SD card files to latest web interface
Added more comments to config.g
Head movement commands that were in the tfree files have been moved to
the tpre files, to work better when G10 nozzle offsets are used