Minor refactoring for easier debugging

* All functions are now named
Moved reusable logic from swagger-validator middleware to swagger-metadata

* This middleware will annotate the request object (req.swagger) with pertinent
  Swagger information based on the request
* This middleware will not annotate the request if the request does not match a
  Swagger defined operation

Fixes issue #9
Update swagger-validator middleware to use/require swagger-metadata