Refactor our validators, only passing them the request object.

This way, we'll be able to use them as cornice service validators.
Pull our colander schema out into bodhi.schemas
Merge branch 'pyramid' into feature/cornice
Add our first cornice service for getting & posting updates
Configuration file cleanups
Refactor our test suite to get it working with cornice
Pull authentication & authorization code out into bodhi.security
Merge branch 'feature/cornice' into pyramid