Use exception instead of failed pattern match
Tests: Expect Exception for wrong C enum conversion
Export Oni type alias
Some Haddocks
Expose ONI_API_VERSION as a constant
Don't ignore Status returned from oniReleaseDeviceList; throw it instead.

oniReleaseDeviceList should never return something else than
StatusOK (in fact, that's what the current implementation does),
but throwing in that case is better than ignoring the return value.
Types: Haddocks
Add OniTimeout
Add waitForAnyStream
Use int/cint instead of fromIntegral.

Makes code clearer and probably safer.
Implement getVersion
Add getExtendedError
Types: Use #const instead of magic numbers
Tests: Add tests for getVersion and getExtendedError