by overloading M32 it is now possible to execute gcode files from other gcode files, with a fixed recursion level.
This can be used e.g. for having a real start.g and end.g somewhere on the sd card, which are then called from the normal print file.
Another usecase would be to have macro-files for nozzle-change and layerchange.
I have not tested the speedwise performance. The testing was done with pronterface.

syntax:
normal call from sd card will open the new file and continue executing there.
M32 !/path/filename#
this however will call the new file and return to the caller file.
M32 P !/path/filename#
with the optional "S<position>" the  file starting position can be set.
this is for continuing prints from a previous location.

if a '#' is read now the buffer will be emptied before reading ahead.
This is so one can execute files from within gcode files, without messing the buffer with preread characters from the caller file.
# can not occure in sd files imho, because it should only occure within checksums in ther serial communication.
Yes, thats a lame argument. If you have a better idea please tell me. It has to be a character that one can type
on a keyboard manually.

This is _not_ automatically the cronological, since deleting a file will free
the filesystem descriptor for it, which then will be used by the next file copied on it.
Since this makes the auto0.g file very inaccessible, I put the option back, to have it in the prepare menu.

this should satisfy https://github.com/ErikZalm/Marlin/pull/373

as a reminder, auto0.g will be executed every time after a boot with sd card present and file present.
thereafter, if there is a file auto1.g this will be done. Thats IMHO the best place to put settings, and prepare heating.
I also execute again after each (now again via the prepare menu) before starting a new print/ after a failed one.
It for me 100% replaces any start.gcode form the slicers.

also, removed some trouble for compilation with corexy.
I think that babystepping is only possible in z for a delta tower.
not sure if it would be usefull to step individual motors on a delta, i don't own one

I strongly vote for it being a single gcode, because otherwise the triggering from the menu is terrible.

It is a realtime control over the head position via the LCD menu system that works _while_ printing.
Using it, one can e.g. tune the z-position in realtime, while printing the first layer.
Also, lost steps can be manually added/removed, but thats not the prime feature.
Stuff is placed into the Tune->Babystep *

It is not possible to have realtime control via gcode sending due to the buffering, so I did not include a gcode yet. However, it could be added, but it movements will not be realtime then.

Historically, a very similar thing was implemented for the "Kaamermaker" project, while Joris was babysitting his offspring, hence the name.

say goodby to fuddling around with the z-axis.

Check the Readme for instruction how to enable and configure the feature

Update Configuration.h

Update pins.h

Include Pins cpu Sethi 3D

Include CPU Sethi 3D

add ENCODER_PULSES_PER_STEP

FIx compilation error when enabling SERVO_ENDSTOPS (#591)

Changed EEPROM CHITCHAT behavior. M503 is always enabled.

Fan fix for Panelolu2+Sanguinololu.

Fixed bug that makes ulticontroller knob backwards introduced Feb 28 201...

Bug introduced in version 6beb42cd.
Robert did a good job of simplifying but messed up this chunk of code.

Looking at working version: 839bef6d
it seems there is no case where encrot3 should be defined as 2
because if ULTICONTROLLER is defined then NEWPANEL is also defined.

Fix the example delta configuration by adding DELTA_DIAGONAL_ROD_2

add command M666 for adjusting delta printer endstop position

Add duplication and auto-park mode for dual x-carriage support.

RAMBo LCD Support, Additional Pins, and Arduino add ons

Improvment for delta, Honeywell thermistor table and move from panel