Implement JSON API HTTP Basic authentication

jsonapi-generator is now capable of generating API for headers outside
  retroshare/ directory
jsonapi-generator do a bit of methods parameter sanity check
JsonApiServer is now integrated in the rsinit hell like other services
Add *::exportGPGKeyPairToString to a bunch of classes in cascade
RsControl is now capable of calling back a function when retroshare is almost
  completely stopped, this is useful when running retroshare toghether with
  externally managed runloop such as QCoreApplication
Expose a bunch of methods through JSON API
retroshare-nogui remove some dead code and fix stopping from the RetroShare API

jsonapi-generator/src/async-method-wrapper-template.cpp.tmpl

@@ -61,5 +61,5 @@ $%outputParamsSerialization%$
 		session->yield(message.str());
 		$%sessionDelayedClose%$
 	} );
-});
+}, $%requiresAuth%$);