config.py: Corrected steps per mm data for Z and E motors

Changed max_speed vector parameter for max feedrate scalar

Signed-off-by: David Jander <djander@gmail.com>
gcode: added support for suppressing extruder movements

This is specially suited for "cold" test runs.

Signed-off-by: David Jander <djander@gmail.com>
Grunner: Corrected feedrates for other than X/Y motors

Added --no-extrusion parameter and implemented proper feedrate limitation.

Signed-off-by: David Jander <djander@gmail.com>
Added clean_extruder shell script.

Run this prior to printing, to heat up the extruder and clean unclog it.

Signed-off-by: David Jander <djander@gmail.com>