Too many DB queries

[etj]

When loading resources, too many SELECTs are performed to retrieve records from gs_stored_data and gs_attributes even when they are not requested / required.
Hibernate annotations should be modified in order to fetch info lazily and not eagerly.

A fix to this issue will also improve the fix for #161.

[simboss]

Priority low? This is making MapStore slow to the point of being unusable in some environments!