Introducing HttpResponseBuilder for creating/configuring HTTP responses.

This commit includes:
- Code clean up
- buffer leak fixes
Cleaning up Transports.
Moving methods from Transports to HttpResponseBuilder.
Inlining HttpResponseBuilder static method calls.
Removing old Cors inbound/outbound handlers.
Renamed Transports to TransportType and made it an enum.
Adding a contentWrappedWithNL to HttpResponseBuilder.
Removing static imports for HttpResponseBuilder for consistency.
Removing CORS handling from Transport implementations.

- This is now handled by the CorsHandler.
Trying to make SockJsHandler more readable.
Inlining response methods as simplify the code.