Adapt nyan to new specification

[heinezen]

Introduces the features discussed for version 1 of the nyan spec.

• [x] Version number (#40)
• [x] dict data type (#68)
• [x] children type modifier (#65)
• [x] optional type modifier (#60)
• [x] abstract type modifier (#62)
• [x] int operations with floats (#83)
• [x] inf/-inf for int and float types
• [x] Change bool value keywords to pythonic spelling

[TheJJ]

I'll continue this in #87