Some refactoring and streamlining for the modelled STS-tests:
* Possibility to ignore certain tests
* Streamlined JUnit execution of modelled tests
* Removed duplicate code related to modelled STS test searching
* Introduced Junit/Assert SCL-module for assertions in SCL tests
* Changed STSTestEditor to extend SCLModuleEditor2
Change-Id: Ib64cf026f69e7490a6eb831afd88d909b80ed8b7