G32 should report bed compensation

[RRP-support]

Three points:

1. G32 should clear any compensation before applying new compensation. I think it adds to any already applied compensation? What's the point of having it add to the current compensation?
2. G32, once complete, should report the bed compensation applied. Perhaps in the form: P0:0mm P1:-0.5mm P2:1mm P3:0.5mm or something similar. This would aid manually levelling the bed, too.
3. It would be useful if there was a command that reported the current compensation, preferably both bed and orthogonal.

[dc42]

G32 already clears any existing compensation. dc42 fork of firmware includes bed compensation in M11 S2 report since before version 0.59.