revert to VB and update to new project file format

Pilz.Drawing.Drawing3D.OpenGLRenderer/Rendering/RenderMode.vb

@@ -0,0 +1,10 @@
+Namespace RenderingN
+
+    Public Enum RenderMode As Byte
+        None = &H0
+        Fill = &H1
+        Outline = &H2
+        FillOutline = Fill Or Outline
+    End Enum
+
+End Namespace