Adds initial bits from bytes support.
Add MACH3 GCode flavor.
Merge branch 'master' into BFB
Fix usage message.
Update some BFB comments.
Merge fix.
Merge branch 'master' into BFB
Merge branch 'master' into BFB
Fix retraction for RepRap.
Reduce the default layer0extrusionwidth a bit.
Merge branch 'BFB'