add Server Diagram to grobdesign.fodt ; fix file layout

doc/grobdesign/server/package.txt

@@ -0,0 +1,73 @@
+// http://www.nomnoml.com/
+#direction: TD
+
+[<package> model|
+    [ «enumeration»
+      + TextureFormat
+    | 
+      JPEG 
+      PNG
+    ]
+    [+ Texture|...]
+    [Sha256|...]
+]
+
+[<package> persistency |
+	
+    [+ DataStore|...]
+    
+    [<package> result|
+      [+ TextureFileResult|...]
+      [+ TextureFileError|...]
+
+      [+ TextureFileResult|...] -/- [+ TextureFileError]
+    ]
+    
+    [<package> search|
+    	[+ Query|...]
+    ]
+    
+    [<package> image_convert|
+    	[+ ConvertConfig|...]
+        |
+        + generate_preview(input, format, config) : ...
+    ]
+    
+    [search] -/- [image_convert]
+]
+
+[<package> protocol| 
+	[<abstract> + ProtocolHandler|...]
+    [+ ProtocolConfig|...] 
+    
+    [+ ProtocolHandler] -/- [+ ProtocolConfig] 
+    
+    [<package> result|
+      [+ ProtocolResult|...] 
+      [+ ProtocolError|...] 
+      [+ ReplaceTextureStatus|...]
+
+      [+ ProtocolResult] -/- [+ ProtocolError] 
+      [+ ProtocolError]  -/- [+ ReplaceTextureStatus]
+    ]
+    |
+    + listen_forever(handler : &ProtocolHandler) : ...
+]
+
+
+[<package> main|
+	[ServerState|...] -- [<note> 
+      implements 
+      protocol::ProtocolHandler
+    ]
+    |
+    + main() 
+]
+
+[main] --> [model]
+[main] --> [protocol]
+[main] --> [persistency]
+
+[protocol] --> [model]
+[persistency] --> [model]
+