- Introduce SourceT, which is simple variant of "correct `ListT`".
There are another variants possible (like in `streaming`),
but I'm not sure there's much real difference.
- Introduce `Codensity`. There's a flag if people don't want to depend
on `kan-extensions`.
- `StreamGenerator` and `ResultStream` are both `SourceT`.
`Stream` combinator in `servant-client` uses `Codensity` for CPS.
- Add servant-machines, servant-conduit, servant-pipes
- Add streaming cookbook: just code, no explanations.
- Add a script to run streaming 'benchmarks'
- Add Streaming endpoint to the comprehensive API.
- Rename BuildFromStream to FromResultStram
- I'm tempted to rename everything in the Servant.API.Stream
(add some prefixes, `header` is too good name to steal)
The TODO in `servant-docs` is left intentionally.
