Speed up the diagonal move while still keeping each individual axis at
or below its homing feedrate.

some guy find that marlin not working good for dual extruders delta .
when type T0 or T1 to active extruder and  E0 or E1  move causing XYZ
motion . so i locales the bugs and fix it , I have dry run the fix.

Extension of M221, Tune menu

Firmware retraction now stores the retract and recover speeds in mm/s
instead of mm/min. This makes it match the units of the maximum
feedrate, and fixes problems with modifying the value via LCD control
panel. From gcode, the values are still taken in mm/min to match the
units of G1 and similar, and they are converted to mm/s before they are
stored.

I also lowered the default retract feedrate to make it less likely to
cause problems for geared extruders when the user hasn’t bothered to
set a reasonable maximum feedrate, though users should be setting both
of these values to suit their hardware.

Added CHDK support to take pictures instead of doing an IR command, see more about how to use it here http://captain-slow.dk/2014/03/09/3d-printing-timelapses/

I made these changes previously, but I can’t find the commit now. This
reapplies the changes to get auto retract working again.

Conflicts:
	Marlin/Configuration_adv.h
	Marlin/Marlin_main.cpp

If position is unknown, then G29 can be dangerous.

This reverts commit 51ae4881ab.

Save above configs in eeprom
fix docs in createTemperatureLookupMarlin.py
add missing azteegX3pro digipot settings in delta example config

This should make it safe to enable FWRETRACT by default, with
autoretract (which should now be fixed) only enabled by M209. FWRETRACT
should probably now default to enabled (to make G10/G11 and M207-209
available, without changing functionality when they are not used), but
I’ll save that for another pull request/discussion.

This takes the (now working) G10/G11 code and moves it to a function,
which is called by G10 and G11, and also called by G1 if autoretract is
enabled and a retract/recover move is detected.

Previous version was broken by using G92 E0 between retract and recover.

 for volumetric E units

Add digipot i2c control for MCP4451
Allow M907 to set i2c digipot currents in amps
Fix Makefile to allow Azteeg motherboards
Fix Makefile to allow Wire libraries only
Add beeper pin for Azteeg X3 Pro

I added #define for LCD_FEEDBACK_FREQUENCY_HZ and
LCD_FEEDBACK_FREQUENCY_DURATION_MS  which is used to alter the default
buzzer sound.

When selecting Panelolu2 in configuration.h:
- it automatically sets the correct ENCODER_PULSES_PER_STEP and
ENCODER_STEPS_PER_MENU_ITEM.
- if LCD_USE_I2C_BUZZER is defined it will also set the default
LCD_FEEDBACK_FREQUENCY_HZ and LCD_FEEDBACK_FREQUENCY_DURATION_MS

When selecting the sanguinololu 1284p the following is true:
- its now enables  LARGE_FLASH
- It enables the gcode M300 when the panelolu2 LCD_USE_I2C_BUZZER is
defined

For some reason that I can’t figure out, the decimal is dropped when
using ’S’ for the code.

Also some minor code improvements to M200.

This is why I wanted to sleep on the code I wrote while falling asleep
rather than immediately submitting a pull request.

This seems to defeat the purpose of previous_millis_cmd, preventing the
time elapsed from previous_millis_cmd from ever reaching
max_inactive_time or stepper_inactive_time while the heat was on.

Fixes a bug in the Extruder Runout Prevention feature that caused the
extruder to move back to “current_position” after a move if it was
activated while the move was in progress. For long home moves (which
are longer than the dimensions of the machine’s working area), this
would cause the machine to crash into the far end of its travel after
homing. This usually occurred on the Z axis, which could result in
damage to the machine if you don’t hit the reset button in time.