No changes
#defines & #ifdef cleanup

Converted axis and tower indexes to symbolic names.
Converted boolean #ifdef's to #if's as needed
Used numeric boolean values in preprocessor per standard
Reduced ~5.4 k line buffer cache to ~1.4k, as it cannot ever
be the speed bottleneck. Reading new gcode lines is many times faster
than even the shortest possible physical move.
Merge pull request #263 from mrbi11/work092

Symbolic index names
Merge branch 'master' into work092
Merge branch 'master' into work092

Conflicts:
	src/ArduinoAVR/Repetier/Commands.cpp
	src/ArduinoAVR/Repetier/Printer.cpp
	src/ArduinoAVR/Repetier/Printer.h
	src/ArduinoAVR/Repetier/motion.cpp
	src/ArduinoAVR/Repetier/motion.h
	src/ArduinoAVR/Repetier/ui.h
	src/ArduinoDUE/Repetier/Commands.cpp
	src/ArduinoDUE/Repetier/Printer.cpp
	src/ArduinoDUE/Repetier/Printer.h
	src/ArduinoDUE/Repetier/motion.cpp
	src/ArduinoDUE/Repetier/motion.h
	src/ArduinoDUE/Repetier/ui.h
	upgrade_instructions.txt
Merged 0.91.7 changes
Changed target for sd pause
Updated gitignore
Merge branch 'master' into work092

Conflicts:
	src/ArduinoAVR/Repetier/Printer.cpp
	src/ArduinoAVR/Repetier/Repetier.depend
	src/ArduinoAVR/Repetier/Repetier.layout
	src/ArduinoAVR/Repetier/SDCard.cpp
	src/ArduinoAVR/Repetier/motion.cpp
	src/ArduinoAVR/Repetier/ui.h
	src/ArduinoDUE/Repetier/Printer.cpp
	src/ArduinoDUE/Repetier/SDCard.cpp
	src/ArduinoDUE/Repetier/motion.cpp
	src/ArduinoDUE/Repetier/ui.h
Maybe fixed Viki startup problem
Merge branch 'master' into work092
Added Megatronics 3 support
Fixed Megatronics 3 pins
Disable motors on startup for inverted enable signals.
Moved sd pin config for due, Minitronics support, Azteeg X1 support
Merge branch 'master' into work092

Conflicts:
	src/ArduinoAVR/Repetier/SDCard.cpp
	src/ArduinoDUE/Repetier/SDCard.cpp
readability maintenance

Makes some mystery numbers descriptive constants
Aligns gcode type structure
Adds option to suppress leading spaces in display format.
Allows status message size of display.
Merge pull request #282 from mrbi11/work092

readability maintenance
Fixed last merge - untested
Fixes for minitronics