NegotiatorExtensions changes

- Changed WithAllowedMediaRange so it won't add the permissable mediarange
if it is already in the collection
- Updated WithMediaRangeModel to use WithAllowMediaRange internally
- Updated WithMediaRangeModel to use TModel instead of dynamic
Clean up

- Renamed MediaRangeModelData to MediaRangeModel
- Added XML comments to MediaRangeModel
Updated NegotiatorExtensions

- Removed old WithMediaRangeModel method code
- Cleaned up XML comments (more consistent now)
Updated NegotiatorExtensions

- Created overloads of all methods and removed With-prefix
- Makes all method with With-prefix as Obsolete