Adjust the Z display to hide float rounding errors

Make hotend optional when compiling with lcd support

Signed-off-by: Matthew Schick <matthew.schick@gmail.com>

Add an item to the LCD menu that applies the current axis position to
the “add_homeing” offset.

G03 Full circle did not work (G02 is working correct)

Add another thermistor table (13),it's a cartridge thermistor up to +300°C,use with Hotend "Simple ONE" & "All In ONE"

Thx

Add another comment for thermistor 13 ,use with Hotend "Simple ONE & All In ONE"

Add another comment on configuration.h for the value of thermistor.
I make a pull request on thermistortables.h with my thermistor (12),but y see there is a comment on configuration with number 12 but it's not present on thermistortables.h ?

Thx

Add another thermistor table,use with hotend "Simple ONE" & "All in ONE"

Corrected retract() call for use of auto probe without sled enabled.

Fix build for non-sled bed auto levelling

This function should only be used with sled, not all bed auto
levelling.

Fix issue 935: error in matrix calculation

Added the new m-codes to this document.

	modified:   Marlin/Configuration.h
	modified:   Marlin/pins.h

Adjusted the  #define PID_dT to reflect 10 A to D sample steps, vs
original 8.

thanks...

The serial protocol has to stay machine readable, without having
to cope with a ton of different human language variants. So
just leave it at the original english version.

Should fix ErikZalm/Marlin#1052

Implemented SCARA-Maths

Fix lcd itostr3() to handle negative numbers

Leapfrog controller board support

temperature.cpp fixes for SD card and MAX6675

FWRETRACT fixes

With option DISABLE_INACTIVE_EXTRUDER the extruder is disable to early

Adding Z Probe via sled mounted endstop

Z probe repeatability with correct defaults

Fix reseting CHDK pin to LOW

This reverts commit 1d0fe035f3.

Update the config file for improvements and clarifying what diameter to
use in the slicer software.

Improvement to avoid reinitializing delay buffer with every print. Fixed
issues in buffer indexing and memory out of bounds due to floating point
imprecision.  Simplified the code by avoiding conversion to standard
diameter and 1cu mm extrusion, which caused complications in determining
mm extruded.

chdkActive was set to false regardless of (millis() - chdkHigh) being bigger than the CHDK_DELAY or not. So if (millis() - chdkHigh) wasn't bigger than the delay the first time, the CHDK would never be set back to LOW.

Also, don't return from the function, as there might be other stuff to do, after the CHDK check.

This snapshot has the Auto Bed Leveling turned off because most Marlin
users do not have that feature.

Z_PROBE_REPEATABILITY test for Auto Bed Leveling.
Implemented as M48 with extra user specified options.
Full support at
http://3dprintboard.com/showthread.php?2802-Auto_Bed_Leveling-Z-Probe-Repeatability-code

This feature allows the printer to read the filament diameter
automatically and adjust the printer in real time.  Added code to read
an analog voltage that represents a filament diameter measurement.  This
measurement is delayed in a ring buffer to compensate for sensors that
are a distance away from the extruder.  The measurement is used to
adjust the volumetric_multiplier for the extruder.  Some additional g
codes (M404, M405, M406, M407) are used to set parameters and turn
on/off the control. g code M221 is updated.  Pins for RAMPS1.4, RAMBO,
and Printrboard are identified for analog input.  The configuration file
is updated with relevant user parameters.

Original code is using WRITE from fastio, but original used pinMode to
set pin direction and did not use the fastio SET_INPUT or SET_OUTPUT.
This caused an issue with the rotary encoder interface to  boards based
on teensyduino, since for teensyduino pin numbers for fastio and the
usual Arduino IO are different.

Fix for a wrong checksum truncation for certain commands

Positioning of string terminator to truncate checksum from the commands
M23, M28, M30, M32, M928 and M117 was off by one, causing the last
letter of the actual command to be truncated instead of just the
checksum.

In case of the SD commands this caused checksummed commands targeting
existing files to fail since the last letter of the filename was
truncated.

In case of M117 this caused the last given letter not to be displayed.

This patch fixes the off-by-one error and sets the null terminator
on the exact position of the * starting the checksum instead of the
character before that.