Switch to JAXRS server implementation

This PR changes the client implementation in `ftw.tika` to talk to a [Tika JAXRS server](http://wiki.apache.org/tika/TikaJAXRS) (HTTP / RESTful) instead of the old builtin server from `tika-app.jar` (plain TCP).

The old TCP server is **not supported** by `ftw.tika >= 2.0` anymore.

### Changes

#### tika.cfg example / testing buildout
- the `bin/tika-server` script now starts a Tika JAX-RS server (`tika-server.jar`), not the builtin CLI server from `tika-app.jar` anymore
- The new server now listens on port `9998` by default
- Buildout sections in the example buildout are now named more precisely (`tika-app-download` and `tika-server-download` instead of just `tika-download`).
- The `*.jar` files are now downloaded from http://repo1.maven.org (`archive.apache.org` doesn't mirror the `tika-server.jar`)
- The Tika version used in the example buildout was bumped to `1.5`

#### Implementation
- The client implementation in `ftw.tika` now expects to talk to a Tika JAXRS HTTP server
- Word bookmarks are stripped from returned plaintext

@phgross @maethu please review

/cc @jone

Yes and no. Integration tests that test the `convert()` method are already being done in [`test_integration.py`](https://github.com/4teamwork/ftw.tika/blob/lg-switch-to-jaxrs-server/ftw/tika/tests/test_integration.py), and the stripping of word bookmarks is already tested in [`test_utils.py`](https://github.com/4teamwork/ftw.tika/blob/lg-switch-to-jaxrs-server/ftw/tika/tests/test_utils.py). In this case we specifically want to `convert_server()` method however, and not accidentally fall back on local tika and not notice.