WFLY-1401 Remove check for valid service names

The JVM is actually much more lenient than the Java language
spec, and pretty much every time this warning has appered it
has been bogus.
Undertow Alpha17
[WFLY-292] Add caching for selected get operations
[WFLY-292] Validate cachable operations against last modified date
[WFLY-292] Add cache header to 304 response
[WFLY-292] Send complete model node for GET operation instead of just the result part
[WFLY-292] Adjust test cases for complete GET response
[WFLY-292] Switch cache validation from last modified date to ETag