minimalist Barcode generator in code128

Fixed problems with both https://github.com/samt/barcode and
https://github.com/emberlabs/barcode.
- Code 128 recognizes pipe ‘|’ character as Type B
- Fixes conflicting definition for ‘type’ in namespace (appears to work
if you use defaults, but if you want another ascii set the problem
appears).
- adds optional label to top of barcode (using offset).