One ether bug (starting the ether after reading config.g) fixed owing to Tony's brilliant debugging persistence.  It still hangs if the ether is unplugged, so that's next on the list.
...Now with correct version number.
G31 now waits for moves to end before measuring/reporting.  G30 implemented.  Has argument Pn n = 0,1,2 - takes probe reading at current XY and calls them point n for the purpose of bed plane calculation.  Add an S field on the last probe (i.e. when n=2 usually, though you can do them in any order) to get it to fit the bed plane.
Manual Z probing added to G30 (see http://reprap.org/wiki/G-code).
Improved functionality for G30; can now be set from pre-recorded
measurements as well as doing live probing (automatic or manual).
M561 reset bed transform to identity added.
Bug found by Tony in the offsetting code fixed (I hope).
Merge remote-tracking branch 'upstream/duet' into duet