Fixed a conflict with HSQLDB

The old version of HSQLDB in 'org.geotools' is causing a conflict with
the latest version of HSQLDB used in the project. An exclusion is made
in 'org.geotools' to fix the problem.
Added user table and data

Updated the schema to include a user table. Added test user data and
initial admin user.
Updated and implemented UserDAO

Implemented and tested UserDAO in JDBC and removed the XML
implementation and test.
Added and implemented UserService

Added a UserService interface with the implementation and test.