Directly use comparaison symbol instead of function name

As the symbol is easier to understand.
Also, update the name of the functions, as the notion of "or equals"
doesn't appear currently.

product/ERP5Form/Extensions/Folder_viewSearchDialog.py

@@ -142,11 +142,11 @@ def getSearchDialog(self, REQUEST=None):
       title=translateString('${key} ${usage}',
                             mapping=dict(key=translateString(column_title),
                                          usage=translateString('Usage'))),
-      items=[(translateString('Equals To'), ''),
-             (translateString('Greater Than'), 'min'),
-             (translateString('Less Than'),'max'),
-             (translateString('Not Greater Than'), 'ngt'),
-             (translateString('Not Less Than'), 'nlt'),
+      items=[(translateString('Equal to'), ''),
+             (translateString('Greater than'), '>'),
+             (translateString('Less than'), '<'),
+             (translateString('Greater than or Equal to'), '>='),
+             (translateString('Less than or Equal to'), '<='),
              ]),
 
                            ['title', 'items'])
@@ -179,11 +179,11 @@ def getSearchDialog(self, REQUEST=None):
         form_id='Base_viewDialogFieldLibrary',
         field_id='your_category'))
     field._surcharged_edit(dict(title=translateString('${key} ${usage}', mapping=dict(key=translateString(column_title), usage=translateString('Usage'))),
-                                items=[(translateString('Equals To'), ''),
-                                       (translateString('Greater Than'), 'min'),
-                                       (translateString('Less Than'),'max'),
-                                       (translateString('Not Greater Than'), 'ngt'),
-                                       (translateString('Not Less Than'), 'nlt'),
+                                items=[(translateString('Equal to'), ''),
+                                       (translateString('Greater than'), '>'),
+                                       (translateString('Less than'), '<'),
+                                       (translateString('Greater than or Equal to'), '>='),
+                                       (translateString('Less than or Equal to'), '<='),
                                        ]),
 
                            ['title', 'items'])