Auto_Bed_Leveling: Enhanced G29 command

[ciutateivissa]

Congrats, very well done!

At the moment I have no time to change the Marlin_Main.cpp but I will give it a try in a few days. My current version of auto-bed-levelings works quite well, but i´m curios to try yours.

For all our friends here which do not have that much experience with this feature it would make some sense if you would add the other settings needed to be done in configuration.h, such as #define NUM_SERVOS aso.