Fix Dynalink compiler warnings

Integrating Dynalink causes Eclipse IDE compiler warnings, as Dynalink uses different settings than Nashorn. The things that were found are:
- unnecessary semicolons
- unnecessary else blocks
- missing switch statement default cases
Also, FacetIntrospector no longer needs to be AutoCloseable since Dynalink ditched using Beans Introspector (there's no resource to close anymore).