many-to-one mapping with composite-id formula fails

Formula and Column should work in exclusion; all formulas or all columns, you shouldn't mix the behavior.

Committed to trunk (revision 5017). Will commit Binder refactoring separately, later.

As I mentioned previously, I don't think this issue should be regarded as a Bug, so I'm changing it to an Improvement.

Attachments: 1) Proposed solution [NH-2117.JM.patch], 2) An updated unit-test [NH-2117.JM.test.patch], 3) Binder refactor [Replace Binder static with instance methods.patch].

Implementation details:

a) NH-only classes:

ValuePropertyBinder - added support for column+formula many-to-one mappings.
ColumnBinder - added overload to support changes in ValuePropertyBinder. Removed assignment of column index. This is redundant as it is performed by SimpleValue when columns are added.
nhibernate-mapping.xsd - Updated many-to-one element, allowing column+formula mappings
HbmManyToOne - Added ColumnsAndFormulas property as ValuePropertyBinder needs the combined many-to-one column+formula mappings in declared order.
ClassCompositeIdBinder - Set Component.IsKey property to true so that ComponentType.ResolveIdentifier does not instantiate the composite ID class if any of the key values are null.

b) Hibernate classes:

ANSIJoinFragment - Encountered bug. Fixed as per Hibernate code-base
SelectFragment - Encountered bug. Fixed as per Hibernate code-base

All tests pass on trunk revision 4985 (HEAD has failing tests due to other work that is going on).

@sthomas: Not sure your issue is the same as the one reported by Richard. I suggest raising a separate Issue for it, and I will do a bit of investigation.

Sorry again for correcting that last example one more time (it's late...):

<many-to-one name="Car" class="Car">
<formula>
'(select c.ID1 from CAR c where c.ID1=CAR_ID1)'
</formula>
<formula>
'(select c.ID2 from CAR c where c.ID2=CAR_ID2)'
</formula>
</many-to-one>