* src/Network/Monitoring/Riemann.hs: better exports and auto append time on send
Ignore .hsenv directory
First version of RiemannT transformer

This is a monad transformer layer you can wrap around pure code. It
lazily collects `Event`s as they're `obs`erved in the monad. These can
be extracted in a pure manner using `observe` or "fired" to a client
using `runRiemannT c` for some `Client` c.
* src/Network/Monitoring/RiemannT.hs: Translated to pipes