ISPN-3973 Upgrade to Resteasy 3.0.7.Final to fix ConcurrentModificationEx

* InterceptorRegistry is no longer in used in this library version because
because JAX-RS 2.0 has its own filter/interceptor API now.
* Remove tests from unstable group.
* Fixed cache entry modified callback expectations in
EmbeddedRestCacheListenerTest to match the current behaviour.