Test the database connection more thoroughly

If the HSQLDB lies on a network share and the computer went into
standby, the connection still indicates that the connection is valid
while it actually is not. Check if a SELECT is posssible and recreate
the connection if not.
Update sdes4j to 1.1.3
Update libjitsi to 5c27d77ffdda40a255eef19d7588e0822c282923