Added support for REFERENCES in CREATE TABLE and ALTER TABLE operations.

I thought it'd be nice to insert foreign key constraints into column creation when references are specified.

This looks at the the information passed in the ```references``` sub-object when the table is defined, so the foreign table and column must both be specified (contrast with the ```joinTo``` syntax).

It's not a big change but I though it'd save a little bit of hand-hacking.

Caveat: I'm pretty new to JS and SQL, so please let me know if anything looks off.