[jvstm-ojb] Better handling of Database Connections.

  * Now using MySQL's NonRegisteringDriver instead of Driver (the latter extends the former)
  * MySQL driver is now manually registered and deregistered
  * Added a static method to DbUtil to ackquire a new DB Connection
New Feature: FenixFrameworkThread

  * Internal threads created by the Framework should now extend FenixFrameworkThread.
  * All FenixFrameworkThread's are shut down whenever the Framework is shut down.
[jvstm-ojb] Removed FenixTransaction.readDomainObject
[jvstm-ojb] Removed JvstmOJBConfig.print()

  * Properties are already printed by the Automatic Initialization system.
Merge pull request #102 from jcarvalho/feature/jvstm-ojb-cleanup

[jvstm-ojb] Cleanups regarding the Framework's shutdown