Fixed "Cooldown" Selection not reseting bed temp

- enquecommand with multiple lines "\n" doesn't work -> M140 S0 didn't
get processed. So I wrote a new func for the cooldown which uses
setTargetHotend. In addition this does return to status page after
selection.
    - Added setWatch() to preheat-functions (Temperatur sanity check
would never have worked when preheating from the lcd panel)

The Viki LCD rotary encoder uses a different number of steps per
rotation. This fixes the seeming "missed" steps when selecting a menu.

added support for the reprapworld keypad

- changed the variables from keypad to reprapworld_keypad
- added a missing ifdef check

BUG Fix in Commands M907,M350 and M351

The for loop for Axis count over the Array.
Add a break after M907

Solved minor bug in controllerFan()

Extruder 2 was checked where extruder 1 should be checked.

If S is left out perhaps it should be silent, but check the spec for
this M code.

Also cosmetic comment changes and spelling corrections in printed
messages

fix DEFAULT_AXIS_STEPS_PER_UNIT minor Z rounding error

(duplicates initialization in Marlin_main.cpp)

Also refactor extruder auto fan logic to simplify further and now only
check every 2.5 seconds

Argument order of lcd_buzz was set to mirror that on tone(). Change
default M300 frequency to something audible.

Conflicts:
	Marlin/Marlin.pde
	Marlin/ultralcd.cpp
	Marlin/ultralcd_implementation_hitachi_HD44780.h

Add (as an option) slower SD transfer mode

128x64 RepRapDiscount Full Graphic Smart Controller support

Make Gen7 1.4+ heater temp sensort pins match silkscreen.

Fix: Build error when EEPROM_SETTINGS is defined and PIDTEMP is undefined

Add new 'callback' edit-menu types that call a function after the edit is done. Use this to display and edit Ki and Kd correctly (removing the scaling first and reapplying it after). Also use it to reset maximum stepwise acceleration rates, after updating mm/s^2 rates via menus. (Previously, changes did nothing to affect planner unless saved back to EEPROM, and the machine reset).

Add calls to updatePID() so that PID loop uses updated values whether set by gcode (it already did this), or by restoring defaults, or loading from EEPROM (it didn't do those last two). Similarly, update the maximum step/s^2 accel rates when the mm/s^2 values are changed - whether by menu edits, restore defaults, or EEPROM read.

Refactor the acceleration rate update logic, and the PID scaling logic, into new functions that can be called from wherever, including the callbacks.

Add menu items to allow the z jerk and e jerk to be viewed/edited in the Control->Motion menu, as per xy jerk.

Conflicts:
	Marlin/language.h