Think about removing riemann dependency

[neshtea]

active-logger contains utilities for connecting and logging to a Riemann instance. While this may come in handy, most projects -- in general -- will not use this. Since most of our Clojure projects (should) depend on active-logger, I find it unnecessary so include Riemann in the bill of materials of every project.

My suggestion would be to pull out the Riemann specific namespace (active.clojure.logger.riemann) and put it in it's own project as a kind of active-logger 'adapter'. This might cause slight overhead, but since I only know of one project that uses the Riemann configuration/appender, it might be worth it,

Thoughts?

[cresh]

Good idea! I'd like to see it go the whole way, though, a full separation of api and backends, see #3.