Bug: if a sql query had a where clause within parens, the entire
clause would be ignored; and instead of it translating to a pql
intersection, it would become an All().
This occured b/c the parser library mapped such an expresstion to
a sqlparser.ParenExpr, and we did not have this as a condition in
a type switch.
So instead of treating a ParenExpr as nothing, we now recurse into
it.
i used this script, a little clunky but it got the job done
```bash
for file in `find . -type f -print | grep '\.go'`; do
sed '1,/^\/\/ limitations under the License.$/d' $file > $file.tmp;
result=`cat $file.tmp`
if [[ result != "" ]]; then
gofmt $file.tmp &> /dev/null;
if [[ $? == 0 ]]; then
mv $file.tmp $file && gofmt -w $file;
else
rm $file.tmp;
fi
else
rm $file.tmp;
fi
done
```
