[eclipselink-dev] checked in fix for bug 322233 into 2.2

[Christopher Delahunt <christopher.delahunt@xxxxxxxxxx>]

https://bugs.eclipse.org/bugs/show_bug.cgi?id=322233
322233 - "Multiple writable mappings exist" when using 
AttributeOverrides and AssociationOverride
- changed foundation so that aggregates store columns as databasefields 
instead of strings
- added new methods to take DatabaseField parameters.  Old methods still 
exist to take strings
- signatures on Public methods within 
AggregateCollectionMapping/EmmbeddableMapping changed to take in maps 
with databasefield values (instead of strings)
- attribute and assocation overrides will now use column and delimiting 
info rather than just set the embeddable's field names. 

Checked into trunk
Reviewed by: Guy Pelletier and Gordon Yorke