Full merge with base Marlin repo, latest commits

The latest Marlin version includes important fixes to homing when auto bed leveling is selected, to avoid the risk of crash between the extruder and the bed.

I checked the diff with your previous version, I am pretty sure that all the Solidoodle-related stuff was kept. I tested on a Sanguinololu and it works fine.

Other additions include: GCode initiated pause (M226) and support for colores LEDs (maybe, didn't look much into that).

Not that this merge restores the proper commit history, it might or might not be desired, it's up to you.