Ignore .nrepl-port

Not sure why there are auxiliary files creeping up one after the other…
Extract routes into a separate component

I have to serve two targets now: development, where I start Jetty at the
REPL and deployment, where a Tomcat (probably) gets a WAR file. Both
need the routing information/a handler function, so it can't stay with
one of them. Therefore take it out of the file with the Jetty stuff and
put it in a separate one.

I also put it into its own component, because it appears to make sense.
But I don't understand the component stuff completely, yet. So I'm not
sure about its proper use.
Prepare for use with Tomcat

On http://thinkrelevance.com/blog/2013/06/04/clojure-workflow-reloaded
and in the video about the component framework (both referenced in the
files) there's some vague information about how to set up the system, so
that it can be deployed to something like Tomcat as a WAR file. And also
how to make the handler non-static.

Puzzle together these information in order to deploy this application to
my local Tomcat. I'm not sure whatsoever if I've put the puzzle together
in the right way. But that will show soon enough when I have to add more
components. Also add the necessary build configuration and some
documentation.