Update cinnamon-menu-editor and cinnamon-desktop-editor

cinnamon-menu-editor:
   Remove item cut/copy/paste from menu editor and add menu category selection to desktop editor instead so that instead of the menu editor adding <Include> and <Exclude> rules to the .menu file when launchers are added to/remove from categories, the desktop editor adds/removes categories to the Categories= field in the .desktop file.
   Remove code related to separators and menu layout/ordering as these are not used in cinnamon applets.
   Add "Restore Item" button and remove "Close" button.
   Handle flatpak apps properly

cinnamon-desktop editor:
   Add menu category selection for launcher editor.
   Add "Hide (NoDisplay)" toggle for launcher editor and directory editor.
   Remove unnecessary <Include> and <Exclude> rules from the .menu file added in previous versions of menu-editor when a .desktop file is updated.

config.py:
   delete unused constants

cinnamon-applications.menu:
   simplify logic in "Administration" menu
   remove unused "System" menu

Author: fredcw

files/etc/xdg/menus/cinnamon-applications.menu

@@ -129,12 +129,6 @@
       </Include>
   </Menu>
 
-  <!-- System Tools-->
-  <Menu>
-    <Name>System</Name>
-    <Directory>cinnamon-system-tools.directory</Directory>    
-  </Menu>   <!-- End System Tools -->
-
   <!-- Other -->
   <Menu>
     <Name>Other</Name>
@@ -176,16 +170,7 @@
     <Name>Administration</Name>
     <Directory>cinnamon-settings-system.directory</Directory>
     <Include>
-      <And>
-        <Category>Settings</Category>
-        <Category>System</Category>
-      </And>
-    </Include>
-    <Include>
-      <And>
-        <Category>System</Category>
-        <Not><Category>Settings</Category></Not>
-      </And>
+      <Category>System</Category>
     </Include>
   </Menu>     <!-- End System Settings -->
 
@@ -199,8 +184,8 @@
 	<Menuname>Office</Menuname>
 	<Menuname>Other</Menuname>
 	<Menuname>Development</Menuname>
+  <Menuname>Science</Menuname>
 	<Menuname>Multimedia</Menuname>
-	<Menuname>System</Menuname>
 	<Menuname>Universal Access</Menuname>
 	<Menuname>wine-wine</Menuname>
 	<Menuname>Preferences</Menuname>

files/usr/bin/cinnamon-menu-editor

@@ -13,14 +13,7 @@ from cme import MainWindow
 
 
 def main():
-    try:
-        from MenuEditor import config
-        datadir = config.pkgdatadir
-        version = config.VERSION
-    except Exception:
-        datadir = '.'
-        version = '0.9'
-    app = MainWindow.MainWindow(datadir, version)
+    app = MainWindow.MainWindow()
     app.run()