[Seaside] VW cgi interface

[danil osipchuk]

> Instead of #addValues:forAttributesNamed:, what about
> 
> (table projectAll: #(attr attr2)) addValues: #('foo' 'bar')?
> 
> Then there wouldn't be any operations that absolutely require you to use 
> a concrete table.
> 
Yes, of course it much more nice.

PS Just noticed, that #projectAll: can receive not only array of names, 
but array of attributes themselvels.
So there should be:
RATestPostrgresSemanticsWithNils>>dropNilColumnFromRelation: aRelation

	^aRelation projectAll:
		(aRelation attributes reject: [:attr | attr name = self nilColumnName])

and all tests are green