190607 c1

- Add Pilz.Drawing.Drawing3D.OpenGLFactory
- Fix small bugs in Pilz.UI.PaintingControl

Pilz.Simple3DFileParser/Other/Exceptions.vb

@@ -0,0 +1,14 @@
+Namespace Exceptions
+
+    Public Class MaterialException
+        Inherits Exception
+
+        Public Sub New()
+            MyBase.New
+        End Sub
+        Public Sub New(message As String)
+            MyBase.New(message)
+        End Sub
+    End Class
+
+End Namespace