Added delete and select helpers with tests.

Minimal helpers for delete (primarily so you dont have to specify the table name) and select (moves away from select *), with some string caching for the generated sql calls.

I didnt see your SimpleQuery project until after this was done, but the same sugar could work well in that project, also.

But, I did break your api a bit (Query became QuerySql because of how Im passing in where clauses), so please dont hesitate to reject this pull request.  I just wanted you to be aware of possible enhancements.

Thanks for all your work,

Jesse