SELECT expressions tests are OK

This mail discharges ACTION-374.

I reviewed the existing 8 project expressions tests, which are all 
already approved by the WG. The tests appear to still be valid with the 
spec, and they do a good job of covering the core areas of project 
expressions, including:

1) multiple project expressions
2) projecting expressions that eval to an error
3) reusing the result of one projected expr in the next expr
4) projecting expression that involve an unbound variable

I do not believe that any further action is required for this part of 
the query test suite.

Lee