Use of thread pools with EJB remote element needs attention

The EJB3RemoteResourceDefinition defines two related attributes:

• an attribute thread-pool-name which is optional and has no default
• an attribute execute-in-worker, which is also optional but has a default "true"

When execute-in-worker == false, the add handler expects the thread pool to be available (the remote connector service introduces a capability dependency on it), but because thread-pool-name is optional, this may not be the case.

If execute-in-worker == false, we need to check and throw an error message if a thread pool attribute value is not available, as we can no longer satisfy this condition (in other words, we cannot delegate the work of processing the method to a thread in the non-existent thread pool).