Make system tests useful

[Petter Måhlén]

Possible solution:

1. invoke ‘system-tests/test.sh’ from top-level pom
2. test.sh knows what output to expect from each sub-directory
3. test.sh gets the path to the plugin from the top level pom (?)
4. test.sh runs that plugin for each test and verifies the output
5. if ok, test.sh returns 0, if not, 1
6. if exit == 1, then the build fails