Merge pull request #18 from InfinitumFramework/orderby

Implement orderBy method for Criteria and supporting SqliteBuilder code ...
Make SqliteDbHelper a singleton class.
Synchronize SqliteTemplate open and close operations.
Implement Session counter.

The counter tracks how many times open() is called and closes the Session only when the count reaches 0.
Remove redundant generic qualifier.
Merge pull request #23 from InfinitumFramework/session-counting

Session counting