static void OnReferenceAdded(object o, ProjectReferenceEventArgs args)
        {
            if (!Util.IsQyotoReference(args.ProjectReference))
                return;

            Project project = args.Project as DotNetProject;
            if (project != null && project.ExtendedProperties["QyotoDesignInfo"] == null)
                QyotoDesignInfo.EnableProject(project);
        }

		protected override void OnReferenceAddedToProject (ProjectReferenceEventArgs e)
		{
			base.OnReferenceAddedToProject (e);

			if (Project.Loading)
				return;

			if (RequiresMicrosoftBuild && e.ProjectReference.ReferenceType == ReferenceType.Project) {
				EnsureReferencedProjectsRequireMSBuild (true);
			}
		}

        static void OnReferenceRemoved(object o, ProjectReferenceEventArgs args)
        {
            if (!Util.IsQyotoReference(args.ProjectReference))
                return;

            DotNetProject dnp = args.Project as DotNetProject;

            if (dnp != null) {
                if (MonoDevelop.Core.Gui.MessageService.Confirm("Qyoto features will be disabled by removing the qt-dotnet reference.", new MonoDevelop.Core.Gui.AlertButton("Disable Qyoto")))
                    QyotoDesignInfo.DisableProject(dnp);
                else
                    dnp.References.Add(new ProjectReference(ReferenceType.Gac, args.ProjectReference.StoredReference));
            }
        }

		void OnRemoveReference (object sender, ProjectReferenceEventArgs e)
		{
			ITreeBuilder tb = Context.GetTreeBuilder (e.Project);
			if (tb != null) {
				if (tb.FindChild (e.ProjectReference, true))
					tb.Remove ();
			}
		}

		void OnReferenceRemoved (object ob, ProjectReferenceEventArgs args)
		{
			if (disposed || !librariesUpdated)
				return;
			string pref = GetReferenceLibraryPath (args.ProjectReference);
			if (pref != null) {
				gproject.RemoveWidgetLibrary (pref);
				SaveProject (false);
			}
		}

		void OnReferenceChanged (object s, ProjectReferenceEventArgs args)
		{
			if (args.Project.ParentSolution == folder.ParentSolution && NUnitProjectTestSuite.IsNUnitReference (args.ProjectReference))
				UpdateTests ();
		}

		protected override void OnReferenceAddedToProject (ProjectReferenceEventArgs e)
		{
			findPipelineEntries(e.ProjectReference);
			base.OnReferenceAddedToProject(e);
		}

		static void OnReferenceRemoved (object o, ProjectReferenceEventArgs args)
		{
			if (updating || !IsGtkReference (args.ProjectReference))
				return;

			DotNetProject dnp = args.Project as DotNetProject;

			if (MessageService.Confirm (GettextCatalog.GetString ("The Gtk# User Interface designer will be disabled by removing the gtk-sharp reference."), new AlertButton (GettextCatalog.GetString ("Disable Designer"))))
				GtkDesignInfo.DisableProject (dnp);
			else
				dnp.References.Add (new ProjectReference (ReferenceType.Gac, args.ProjectReference.StoredReference));
		}

		void OnRemoveReference (object sender, ProjectReferenceEventArgs e)
		{
			var p = e.Project as DotNetProject;
			if (p != null) {
				ITreeBuilder tb = Context.GetTreeBuilder (p.References);
				if (tb != null && tb.FindChild (e.ProjectReference, true))
					tb.Remove ();
			}
		}

		protected override void OnReferenceAddedToProject (ProjectReferenceEventArgs e)
		{
			base.OnReferenceAddedToProject (e);

			DotNetProject project = GetDotNetProject (e.ProjectReference);
			if (project != null) {
				EnsureBuildPackagingNuGetPackageIsInstalled (project);
			}
		}

 void OnAddReference(object sender, ProjectReferenceEventArgs e)
 {
     var p = e.Project as AbstractDProject;
     if (p != null) {
         var tb = Context.GetTreeBuilder (p.References);
         if (tb != null)
             tb.AddChild (e.ProjectReference);
     }
 }

		protected override void OnReferenceRemovedFromProject (ProjectReferenceEventArgs e)
		{
			//short-circuit if the project is being deserialised
			if (Project.Loading) {
				base.OnReferenceAddedToProject (e);
				return;
			}

			UpdateWebConfigRefs ();

			base.OnReferenceRemovedFromProject (e);
		}

			internal protected override void OnReferenceRemovedFromProject (ProjectReferenceEventArgs e)
			{
				Project.OnReferenceRemovedFromProject (e);
			}

			internal protected override void OnReferenceAddedToProject (ProjectReferenceEventArgs e)
			{
				Project.OnReferenceAddedToProject (e);
			}

		internal protected virtual void OnReferenceRemovedFromProject (ProjectReferenceEventArgs e)
		{
			next.OnReferenceRemovedFromProject (e);
		}

		internal protected virtual void OnReferenceAddedToProject (ProjectReferenceEventArgs e)
		{
			next.OnReferenceAddedToProject (e);
		}

        protected override void OnReferenceRemovedFromProject(ProjectReferenceEventArgs e)
        {
            base.OnReferenceRemovedFromProject (e);

            if (addingReferences)
                return;

            if (e.ProjectReference.ReferenceType == ReferenceType.Project) {
                var jsonFile = ProjectJsonFile.Read (this);
                if (jsonFile.Exists) {
                    jsonFile.RemoveProjectReference (e.ProjectReference);
                    jsonFile.Save ();
                    FileService.NotifyFileChanged (jsonFile.Path);
                } else {
                    LoggingService.LogDebug ("Unable to find project.json '{0}'", jsonFile.Path);
                }
            }
        }

		static void OnProjectReferenceRemoved (object sender, ProjectReferenceEventArgs args)
		{
			ProjectDom db = GetProjectDom (args.Project);
			if (db != null) {
				db.OnProjectReferenceRemoved (args.ProjectReference);
			}
		}

		void ProjectReferenceRemovedFromProject (object sender, ProjectReferenceEventArgs e)
		{
		}

		void OnAddReference (object sender, ProjectReferenceEventArgs e)
		{
			DotNetProject p = e.Project as DotNetProject;
			if (p != null) {
				ITreeBuilder tb = Context.GetTreeBuilder (p.References);
				if (tb != null)
					tb.AddChild (e.ProjectReference);
			}
		}