Added ContentType as an internal property on BrowserResponseBodyWrapper
Made serializer in BrowserResponseBodyWrapper extensions pluggable
Updated NancyContext.ModelValidationResult

It will not use ModelValidationResult.Valid, instead of newing up a
blank result, when no result has explicitly been assigned to the
property.
Fixed XML comment of ModelValidationDescriptor
Updated ModelValidationResult and ModelValidationError

Instead of errors being represented by a simple
IList<ModelValidationError> structure, it is not stored in an
IDictionary<string, IList<ModelValidationError>> structure. The key is the
name of the property that the error represents.

The error message formatter has also been updated from Func<string,
string> to Func<IEnumerable<string>, string> since MemberNames can contain
multiple values

Last, the ModelValidationError can now implicitly be cast to a string
Fixed broken tests
Added missing XML comment
Added WithMediaRangeResponse ext to Negotiator
Made ResponseProcessor media range neutral
Merge pull request #1339 from thecodejunkie/conneg-mediarange-response-model

Conneg mediarange response model
Ported all constraint methods to IRouteConstraints
Removed constraint methods and replaced them with IRouteConstraints
Fixed some minor issues with demo project
Updated demo project with a custom route constraint
Renamed RouteConstaint to RouteSegmentConstraint
Added DateTime constraint with format parameter
Added IResponseProcessors back in
Added 'Base' suffix to ParameterizedRouteSegmentConstraint
Added XML documentation to public/protected members
Merge pull request #1277 from khellang/configurable-route-constraints

Configurable route segment constraints