* Documentation

** Automagic generation

We already have this, but it would be good to be able to override for
certain functions.

** Online/texinfo docs

Need to figure out how to categorize functions, etc.

** Type documentation

** signals, properties

** inheritance

For me to call cairo docs finished, i'd want sectioned function docs,
with autoconverted headers.

* Tests

At the very least, a test that ensures that the API stays the same: same
set of symbols exported.