* Fission OGS1UserServices into user service and OGS1 user data plugin components

* Make OGS1UserServices inherit from UserManagerBase
* This allows grid mode regions to use the same user data plugin infrastructure as grid servers and standalone OpenSims

OpenSim/Tests/Common/Mock/TestUserDataPlugin.cs

@@ -86,6 +86,8 @@ namespace OpenSim.Tests.Common.Mock
 
             return userProfile;
         }
+        
+        public UserProfileData GetUserByUri(Uri uri) { return null; }
 
         public bool UpdateUserProfile(UserProfileData user)
         {