M666 Probe Offsets, G30 Probe Speed, Calibration Report

Added the ability to change autocalibration probe offsets like M666 P Xnn Ynn Znn. The original M666 Pnn still works to change only the Z offset.

Added ability to change the probing speed of G30 (not yet G29) like G30 A Fnnn (requires a new config variable PROBING_FEEDRATE)

Fixed layout of autocalibration report for Repetier Host (Host seems to barf on printing a string containing "B"