Java/servlet code cleanup

[zloster]

Areas that need improvement:

• Servlet code duplication for the db tests. The only difference is the annotation which is injecting the datasource - using DataSource with the same name and different parameters
• The exception handling currently is swallowing the exceptions - the lost Async servlets were having good production grade error-handling
• Move the application to the root context to have shorter URLs. Currently it is http://TFB-server/servlet/plaintext - Moved to Move Servlet application to the root context to have shorter URLs.  #42
• Check if there is actual difference in the performance if the DB connection pool is using the recommended DB driver class or maybe it will help with the transaction deadlocks? - Moved to Check if there is actual difference in the performance if the DB connection pool is using the recommended DB driver class #43