Xtext tool service not proxied

[barnettwilliam]

The Xtext tool service is not configure to proxy requests in a similar manner to other tool services. This means that tool service appears as a separate location rather than the same location.

The tool config is located: 127.0.0.1:8074
The service located 127.0.0.1:9000

Requests to 127.0.0.1:8047/services/xtext should be forwarded to the :9000 service. This is so the convention used by other services is followed and enables the use of tool service URL re-write functionality introduced in mdenet/educationplatform#162.