Fixes #10 - INSERT statements broken

    The problem is that we are using === to check if the value is null
    when we really want to know if the attribute is null or undefined.  This
    fix uses type coercion to our advantage.
Merge pull request #11 from simplyb/10_broken_inserts

Fixes #10 - INSERT statements broken
0.0.18
fix for in queries in pg
0.0.19