Updates for 4.0.8 Snapshot
Moved exceptions into business commons package in model
Renamed abstract DiskCache class to a more appropriate name -- one client implementation outside of core has a more advanced version which extends the existing non-disk based dao implemenation.--Much less repeated code.
Converted classes using EntityRefQuery to use EntityQuery, and included a base class.  The classes were almost identical.
Removed unused data structures in memory db these were going to be optimizations that never materialized.
Clean up of some memorydb related classes
Added new relationship types, visual types, symbol constants and canonical property types.
Removed unused model, view and query objects.
Updated Tapestry UI menu layout