Integrated fixes from henrikbrixandersen pull request #504

merged from code downloaded from reprapworld.com

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

The LARGE_FLASH flag allows superfluous features to be excluded
on boards with less memory

These definition contain also the definition for the graphics LCD.

These definition contain also the definition for the graphics LCD.

This includes refactoring the buttons code to remove a large amount of
non-pin dependent duplication from pins.h.

Controller. Remove common definitions. Harmonize declaration order.

Change required after pulling from ErikZalm.

Took out the ifdef when I split 1.4 out and forgot to permanently
define it for <=1.3.

motor current and microstepping pins.

Gen7 1.4 uses very different pin assignments, might as well make a new
section and remove some of the conditionals from each. It's easier to change
your pin assingment this way if like me you don't wire it exactly to plan.

HOME_POS is now always where the endstop is and can be outside the limits.
The limits are now defined by MIN_POS and MAX_POS rather than HOME_POS and MAX_LENGTH.
The Z is axis now homed first if direction is away from the bed.

Saguinololu limit pins change from MIN to MAX according to the homing direction.