Add enums for arduino pro model variants

- Add headerless example to the sandbox
- Adjust Breadboard assembly to match
Add header pins (optionally) to ArduinoPro models

- Also show pins in Breadboard assembly
Only show minimum clearance with no header pins
Increase indentation to match project style
Add some break-away material for headers

todo: rotate material location based on vector
Merge pull request #30 from snhack/arduinopro-vitamin

Arduino Pro Vitamin