INT-2875 Fix CPU Usage In JMS Test

Reply Container was spinning receiving StubMessages.

Set auto-startup to false on the gateways configured with
a <reply-listener/>.
Merge pull request #700 from garyrussell/INT-2875

* garyrussell-INT-2875:
  INT-2875 Fix CPU Usage In JMS Test
INT-2864 Enforce Ref/Expression Mutual Exclusivity

Delegating consumer endpoints (<service-activator/> etc)
may not have both 'expression' and 'ref' attributes.
Previously, 'expression' was ignored when 'ref' was present.

- Enforce mutual exclusivity in AbstractDelegatingEndpointParser.
- Add tests for illegal combinations.
- Improve error message when 'method' used with <expression/>.
- Change parser to use reader.error() instead of Assert.
- Add element description to all parser errors.