INT-2912 JdbcMessageStore Add 'region' to Queries

Missing region column in some queries.

For reference see: https://jira.springsource.org/browse/INT-2912

INT-2912 - Code Review
* Eliminate Spring Application Context for Test
* Improve SQL Query

INT-2912 Polishing

Modified testVerifyMessageGroupCount to test size of each
group in each region.
Merge pull request #729 from ghillert/INT-2912