Merged *next branch* into master with the following changes:
Porting ddprint to Ender5 (pro):
* Changes for the Creality melzi board (atmega1284p based).
* Added thermistor table for epcos 100k ntc.
* Declared IO-pins in firmware/pins_ender3.h
* Rework homing:
+ use feedrate and direction for homing from printerprofile.
+ Move away from nozzle after z is homed (for printers that
home at z=0. This is to avoid scratching over the bed when
homing X and Y.
+ Homing: added "4 point mode" for ender.
* Added new script *thermistor_table.py* to generate thermistor
* Host: rework *getstatus* and *mon* commands.
* Host: filament profile measurement:
+ measure2: increase printing speed with fixed
temperature while monitoring feeder grip.
+ measure2: changes to reduce heating effect of
heated bed, start measurement on fifth layer.
+ specify minimum grip value on commandline (instead of
+ write measured material profile to ./mat-profile2.add.
* Host, *removefilament* command: changed feeding
sequence to avoid filament plug.
* Host, Experimental: added *reconnect* command.
To reconnect to a running printer, works after
download is complete, but not if disconnected
while downloading stepper data.
* Host: Added *ddprint version* command.
* Firmware: cleanup flowrate measurement,
measure short moves, too.
* Firmware: added CmdGetVersion command.
* Firmware, Makefile: new target *make gitversion.cpp*
* Firmware: set printer state to idle if steppers are
disabled (cmd *disablesteppers*).
* Firmware: Update to SdFat-1.1.4 library (USE_SD_CRC enabled).
* Firmware: Rework mass storage erase: new commands CmdGetCardSize
and CmdErase. Call erase before printing.
* Firmware: Sd card init: retry up to 5 times.
* Many smaller fixes/improvements