Allow ack mode to be specified in non-transactional MDBs

According to the EJB 3.0 specification, if bean-managed transaction demarcation
is being used it should be possible to configure the acknowledgement mode
required. This is not currently possible in GenericJMSRA.

From the EJB 3.0 Core spec (Section 5.4.14 "Message Acknowledgment for JMS
Message-Driven Beans"):

"If bean-managed transaction demarcation is used, the Bean Provider can indicate
whether JMS AUTO_ACKNOWLEDGE semantics or DUPS_OK_ACKNOWLEDGE semantics should
apply by using the activationConfig element of the MessageDriven annotation or
by using the activation-config-property deployment descriptor element. The
property name used to specify the acknowledgment mode is acknowledgeMode. If the
acknowledgeMode property is not specified, JMS AUTO_ACKNOWLEDGE semantics are
assumed. The value of the acknowledgeMode property must be either
Auto-acknowledge or Dups-ok-acknowledge for a JMS message-driven bean."

In addition, although the EJB 3.0 spec is not specific on this matter, it should
be possible to use the same configuration to specify the acknowledge mode used
when a MDB is deployed using CMT and the transactional attribute is notSupported.
#### Environment
Operating System: All
Platform: All
#### Affected Versions
[2.1a]