Remove controller dispatch and related dependencies

Okay, let's try this again. Since controller dispatch has been deprecated for some time now, I decided to remove that and all of its related dependencies (including Sinatra!). I think this simplifies things by an order of magnitude.

Because the framework extensions were requiring `params_verification` I moved that into `lib/weasel_diesel` or else it will only be available as an optional module. Let me know if you disagree with this change and I can modify.