Fix #30 - unable to save edited value of 'zoomLevel' in users preferences
Removed localized strings from datetime format for GET requests
Fixed 'undefined' values parsing
Updated hungarian translation - thanks to @vzoltan
Added additional code to prevent bug identified in #22 and #23;  Duplicated pattern used for admin.
Updated the Hibernate plugins (mostly to support JPA 2.1); Added PostgreSQL driver to match traccar pom.xml.
Removed Hibernate-specific code and replace with JPA equivalents.
Made all id's use GenerationType.IDENTITY; Replaced wildcard imports with specifics.
Formally named unique and foreign keys.
Fixed typo in query