Finagle-Postgres support

[vkostyukov]

It would be abolutelly awesome to support finagle-postgres in Quill. I'm might volunteer and give it a try, althought I can't promise any progress in the nearest feature, so I decided to open an issue so anyone else can pick it up.

[fwbrasil]

Thanks for creating this issue @vkostyukov. postgresql-async has some performance issues, so It'd be nice to have an alternative!

It should be straightforward to implement using quill-finagle-mysql as example. There are two things that seem to be different though:

1. I couldn't find transaction support in finagle-postgres. Is it available?
2. The encoders and decoders will be a bit different since finagle-postgres doesn't provide a high-level api for parameters and results as finagle-mysql does.

Let me know if I can be of any help.

[jilen]

The new finagle-postgres implementation is call roc