Flattened base class into AllRequestHandler as it was the only subclass
Route params logic from base class is now in RouteParamsSubstitutor
Rename "AllRequestHandler" to just "RequestHandler"
Also GetRequestHandlerTests and PostRequestHandlerTests now both test this class
so they are RequestHandlerGetTests and RequestHandlerPostTests
added an interface to RequestHandler
Merge pull request #130 from AnthonySteele/SimplerRequestHandler

Simpler request handler