Split GeoTools based classes into own modules

The default build will no more include any GeoTools dependencies. GeoTools based modules are still build, as the are needed for testing, but to include them in the webapp the `with-geotools` profile has to be activated (has also to be activated to run the integration tests, as documented in the `README.md`).

Most notable changes: 

* AGS, Python, R, GRASS, MovingCode, Sextante and Transactional backends are no longer included
* `GTReferencingEnvelope` was replaced by a generic `BoundingBoxData` class
* `FeedServlet` and associated classes are moved to `52-wps-mc`
* some changes regarding `wps_config.xml` file handling (see #60 and the `README.md` changes).

I didn't find a way to exclude GeoTools from the notice file, as it is still required for tests…

As a nice side effect the WAR file shrunk from 58 MB to 28 MB :)

(Integration) tests pass, but some testing is welcome…