Migrated PaintCode to unified API

- Cast nfloat to float
- CGContect.SetShadowWithColor to .SetShadow
- Changed float[] to nfloat[] so that its contained values can be used
as 'out' parameters
- Changed float[] to nfloat[] to be used as constructor parameter
- Enclosed negative value in parentheses in order to be cast
- Removed (nfloat&) cast from 'out' method parameters