INT-2911 IO Exceptions Not Logged as ERROR

TcpNetConnection IO errors were only logged under DEBUG.

* Code was added to suppress the error log when the exception was due to a normal close. This inadvertently suppressed all ERROR logs.
* Capture a local copy of this.noReadErrorOnClose before closing the socket after an exception.
* Add test case to ensure ERROR log is emitted.
Merge pull request #728 from garyrussell/INT-2911

* garyrussell-INT-2911:
  INT-2911 IO Exceptions Not Logged as ERROR
INT-2900 Remove Extraneous Debug Log

When referencing a <gateway/> from a <service-activator/>, a debug
log is written with a full stack trace.

This is because all methods on the proxy are considered candidates,
but one method (addAdvice) has multiple parameters and can't be
used to process a message.

Add code to detect a proxy that has no target object; if the Proxy
only has one interface, then use that as the targetClass.
Merge pull request #733 from garyrussell/INT-2900

* INT-2900: Remove Extraneous Debug Log