WIP on move to dispatcher cont'd

Changes in this commit:

1. Functions which will no longer be required once the move to the new
   dispatch mechanism is completed are removed.

2. A few more steps towards moving the test suite over to the new
   dispatch mechanism. A handful of tests remains commented out; these
   rely on Compojure's context and/or the internals of the old dispatch
   mechanism and will have to be rewritten or removed.

3. Some documentation tweaks -- most notably,
   io.aviso.rook/namespace-handler now sports a proper docstring.

4. pprint-code now lives in io.aviso.rook.utils.