Integrate Jesery w/ Guice DI and sample Hibernate configuration

This commit contains more of the application barebones, wiring together
the core components. Guice has been implemented and will dependency
inject our Jersey services.

At the moment, we have a mock implementation of the user service that
just stores account information to memory. The server will respond to
the following restful calls:

 - %HOSTNAME%/rest/users/register
 - %HOSTNAME%/rest/users/login

The user service is injected and can be swapped for the RMBS/Hibernate
version by modifying the module configuration - see GuiceServletConfig

At this stage, Hibernate is integrated but not utilized.