Alpha-release. Expect bugs.
Changes:
- API change for NumPy interoperability
- Buffer protocol improvement for various color types
- Support `__array__interface__` and `tobytes` for `PIL.Image` interoperability
- Support with-context in `Surface.getCanvas`, `Document`, `Document.beginPage`, and `FILEStream`
- Improve gpu API bindings
- Add missing PDF APIs
- Fix return value policy on context manager and iterators
Known issues:
- Missing APIs: 57