Test case and documentation for calling stored procedures with transaction control.

[draderaws]

Add documentation and unit test for calling stored procedures that use transaction control. Update existing callproc doc to refer to functions and procedures. Add error code returned from server if stored proc with transaction control is called from inside a transaction.

All Submissions:

• [Yes] Have you followed the guidelines in our Contributing document? Yes
• [Yes] Have you checked to ensure there aren't other open Pull Requests for the same update/change? Yes

1. [yes] Does your submission pass tests?
2. [yes] Does mvn checkstyle:check pass ?
3. [yes] Have you added your new test classes to an existing test suite in alphabetical order?

• [no] Does this break existing behaviour? If so please explain.
• [yes] Have you written new tests for your core changes, as applicable? new test, not core change.
• [yes] Have you successfully run tests with your changes locally?