Added database creation tests

While testing, it was discovered that c strings do not play nice. Since this is a fringe feature, it was removed.
Added support for regex and like predicates
Added better support for NSPredicate LIKE

Rather than try to map the predicate to SQL LIKE, we created our own. Apparently, SQLite defines LIKE as a user function, so we shouldn't see a performance hit.
Added caching to regular expressions

Now a regular expression object will only be created once, and then cached. This should be a huge performance win for large datasets, and common regexp queries.