refactored dir structure, cleaned some inx files, removed unrequired deps

extensions/fablabchemnitz/cleangroups/cleangroups.inx

@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<inkscape-extension xmlns="http://www.inkscape.org/namespace/inkscape/extension">
+    <name>Remove Empty Groups</name>
+    <id>fablabchemnitz.de.cleangroups</id>
+    <effect needs-live-preview="false">
+        <object-type>path</object-type>
+        <effects-menu>
+            <submenu name="FabLab Chemnitz">
+                <submenu name="Groups and Layers"/>
+            </submenu>
+        </effects-menu>
+    </effect>
+    <script>
+        <command location="inx" interpreter="python">cleangroups.py</command>
+    </script>
+</inkscape-extension>

extensions/fablabchemnitz/cleangroups/cleangroups.py

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+#!/usr/bin/env python3
+
+import inkex
+
+"""
+Extension for InkScape 1.0
+
+This extension is totally minimal. It will just clean the whole document from groups without content (dangling groups). That usually happens if you have a group but remove it's paths for example. The group will possibly stay in the XML tree. This also applies for layers because layers are just special types of groups. This effect applies to the whole document ONLY!
+ 
+Author: Mario Voigt / FabLab Chemnitz
+Mail: mario.voigt@stadtfabrikanten.org
+Date: 19.08.2020
+Last Patch: 01.04.2021
+License: GNU GPL v3
+"""
+
+class CleanGroups(inkex.EffectExtension):
+     
+    def effect(self):
+        while True: 
+            groups = self.document.xpath('//svg:g',namespaces=inkex.NSS)
+            oldLen = len(groups)
+            #leave the loop if there are no groups at all
+            if len(groups) == 0:
+                break
+            #loop trough groups. we have minimum of one to check for emptyness
+            for group in groups:
+                if len(group.getchildren()) == 0 and group.getparent() is not None:
+                    group.getparent().remove(group) #deletes the deepest empty group
+                    continue #we found minimum of one element to delete. so we should run another cycle to check if the parent of this group is empty after deletion
+            newLen = len(self.document.xpath('//svg:g',namespaces=inkex.NSS))
+            if newLen == oldLen: #found no more empty groups. Leaving the loop
+                break
+            
+if __name__ == '__main__':            
+    CleanGroups().run()