Added prefix, suffix, and pattern searching

* Added prefix matching on string columns (see Query.startswith())
* Added suffix matching on string columns (see Query.endswith())
* Added pattern matching with prefix optimizations on string columns (see Query.like())
* Added cached query result exposure
* Enabled Lua support by default
* Bumped version
* Updated copyright notice
* Updated readme to offer an example suffix query
* Fixed issue where a user could specify more than one primary key column, which could lead to inconsistent queries, lost data, and more
* Made query validation more consistently used