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