Merge pull request #2 from ErikZalm/Marlin_v1

Sync up to Marlin
Commented out FILAMENT_SENSOR #define

Commented out the FILAMENT_SENSOR define so that it is not enabled by
default.  Code does not work on all hardware variants.
Merge pull request #1138 from filipmu/Marlin_v1

Comment out the FILAMENT_SENSOR define by default in config.