Add support for registering with a threepid to the HS (get credentials from the client and check them against an ID server).

synapse/rest/register.py

@@ -47,10 +47,15 @@ class RegisterRestServlet(RestServlet):
         except KeyError:
             pass  # user_id is optional
 
+        threepidCreds = None
+        if 'threepidCreds' in register_json:
+            threepidCreds = register_json['threepidCreds']
+
         handler = self.handlers.registration_handler
         (user_id, token) = yield handler.register(
             localpart=desired_user_id,
-            password=password)
+            password=password,
+            threepidCreds=threepidCreds)
 
         result = {
             "user_id": user_id,