Route Loading Scheduling - Fixes #8

Realized that I had two schedules, one for the route-loading and one for
the normal config loading. While I could just get rid of the normal config
loading, we need to guard against anyone sending another config load request
anyways (just the right thing to do). The the cancellable is kept now in
the ConfigLoaderActor's internal state.
Merge pull request #8 from JohnMurray/issue-8

Load Routes is scheduled more than once