* Variables Kp, Ki, Kd, Kc now arrays of size EXTRUDERS
* M301 gains (optional, default=0) E parameter to define which
extruder's settings to modify. Tested, works with Repetier Host's EEPROM
config window, albeit only reads/updates settings for E0.
* All Kp, Ki, Kd, Kc parameters saved in EEPROM (version now v14), up to
3 extruders supported (same as Marlin in general)

logo is now 110 pixels wide and starts 9 pixels in from top left corner and also 9 pixels down from same corner... this will give a 9 pixel border all way round

ver info is placed centered and there is a 9 pixel from bottom of display to ver info

The previous calc was wrong. Between N points there are only N-1 gaps,
not N.

So changing AUTO_BED_LEVELING_GRID_POINTS to
(AUTO_BED_LEVELING_GRID_POINTS-1)

Documentation restructuring

Conflicts:
	README.md

Documentation directory

(For the SLOW_PWM_HEATERS option)

Fix grammar/typos in new Configuration.h option

Revert "issue 968 for dev branch"

(For the SLOW_PWM_HEATERS option)