Change Z travel acceleration to decrease noise

change Z travel acceleration from 100 to 150 in eeprom and repetier make
Z movement less noisy
Add Clean Nozzle function

In quick settings add new clean nozzle function, it is also available
using M100 command
It do home if not done and ensure bed is at least 15 mm it is supposed
ok on DaVinci 1.0 and 2.0 Configuration.h has new parameter to enable
and control movement

I changed the way the Clean Nozzle function works, making it more
flexible and allowing it to work with other 3D Printers.

Also fixed uimenu.h to fix compile errors when using SIMPLE_MENU with
Dual Extruders.
Extruder temp being read wrong on Da Vinci 1.0

Extruder temp was being read wrong on Da Vinci 1.0.
It would appear as if it was stuck at 70 C, and would not increase /
decrease (Which will cause overheat).

This was due to NUM_EXTRUDER not being set before calling #include
"pins.h".

I changed the way this function works, and everything should be fine
now.