Added transaction support at the connection level and added implicit rollback to releaseConnection at the pool level.
Changed inTransaction to toggle on callback.  Added transaction begin/commit/rollback error messages and tests.
Added documentation for transactions
Changed transaction documentation to be more succinct.
Error in transaction documentation.
Changed transaction documentation to be more succinct (again).
Removed transactions from TODO list
Changed that usage to self.  connection.changeUser now sets inTransaction to false.
Changed to simple transaction support.  Updated documentation to point to MySQL transaction documentation.
Fixed link in documentation
Merge pull request #586 from jflitton/master

Basic transaction support for connections