JBIDE-15593 - Change WS Tester parm validation to warning, not error, so
user can submit request with bad parms if desired
JBIDE-15548 - Use JUnit @Rules instead of inheritance in test cases
JBIDE-15827 - Failed to remove JAX-RS Metamodel when closing a project

Removed the call to delete markers on project while it was being closed, which
was not necessary and caused the reported CoreException.