Some more refactoring

Renamed some classes with better names;
* httprpccontext->httpservicecontext
* httprpcresponse->httpservicerequest
* socketsrpcrequeest->socketservicerequest
* socketsrpccontext->socketsservicecontext

Fixed httpservicerequest vanillaminer.parse() implementation.
Implemented ivanillaserverconfig and istratumserverconfig which they take distinct config variables.
Added IServiceFactory.cs and ServiceFactory.cs and assoc. registry.
Fixed serverFactory.Get call.
Fixed back deps/json-rpc.net commit.