#98 [Bug] db connections not closed on exceptions

[Hendrikus]

In case of an exception it can happen that the database connection is not returned to the pool.

This is a very serious bug, because it will cause the transaction pool to run out of connections.
---> the next thread requesting one will block
---> apache will eat up all threads
---> http://stendhal.game-host.org is not reachable anymore
---> the Stendhal client hangs on the version check for 5 minutes.
---> Nobody waits for 300 seconds to connect to the Stendhal server