#5 Parser doesn't support SELECT xforms

[Sam Madden]

Queries of the form:

select light + 10

Don't work.

Oddly enough, queries like:

select AVG(light + 10)

do.

This is because the latter are treated as expressions
in TinyDB, whereas the former is merely a part of the
select list. We could change the java front end to
apply transforms like the former, or wedge it into TinyDB.