* Control.cs: Enable OnPaintInternal so we can use it for drawing

* Control.cs: Enable OnPaintInternal so we can use it for drawing
        all of our controls instead of Paint +=.
        * ListBox.cs:
        * ListView.cs:
        * MenuAPI.cs:
        * MessageBox.cs:
        * NotifyIcon.cs:
        * ProgressBar.cs:
        * ScrollBar.cs:
        * Splitter.cs:
        * StatusBar.cs:
        * TabControl.cs:
        * TextBoxBase.cs:
        * ToolBar.cs:
        * TrackBar.cs:
        * UpDownBase.cs:
        * ComboBox.cs: Remove handling of WM_PAINT and WM_ERASEBKGND and
        use OnPaintInternal. Remove Width/Height and Visible checks in
        paint handler, this is done at a higher level now.
        * GroupBox.cs: Don't need to handle WM_ERASEBKGND anymore.
        * PaintEventArgs.cs: Add a handled flag so controls that don't
        want anymore painting after OnPaintInternal can make sure
OnPaint
        isn't called.

svn path=/trunk/mcs/; revision=59104