Renamed NamedUserProvider to SingleUserProvider
Refactored the different feature maps to single FeatureMap class
Code formatting
Refactoring of the property feature provider

* PropertyBasedFeatureProvider -> PropertyFeatureProvider
* Moved specific feature group implementation to more general class
* More test coverage
Added JSP taglib that uses Spring context to retrieve the active features map.
Refactored JSP tag to separate togglz-jsp module
Fixed JDBCStateRepository schema issue with PostgreSQL #(38)
Fixed JDBCRepositoryTest to reset database before executing the test