Create "Advanced Circuits 4-layer.dru" - design rule file for Advanced Circuits $66 4-layer boards
Update OSH Park 4-layer with references and remove (draft) label.
Merge pull request #35 from aaronbeekay/DRU_updates

DRU updates (Advanced Circuits and OSH Park 4-layer)
Remove "C | elec" frame (outdated)
Update Current C logo in 0.25" height to be polygon instead of raster
Merge pull request #36 from aaronbeekay/Logos

Update Current logos and frames