The code that was intended to handle this preference looked inside
Mod/BIM instad of Mod/Draft for the preference. This seems to have been
broken since the preference was first introduced in commit 9976a5ece0
(Draft: Turned autogroup button into layers selector (added pref option
to restore old groups-based system)).
This also removes a stray "-" that was probably a leftover from a merge
conflict, introduced in commit 0547d23660 (Draft: move Draft_AutoGroup to
gui_groups module). Since -True is still true and -False is still false,
this did not actually break the code, though.
See https://forum.freecadweb.org/viewtopic.php?t=42018 for related
discussion.
These functions were previously in `draftutils.utils`,
and are related to grouping objects and finding objects
inside groups. These include `get_group_names`, `ungroup`,
`get_windows`, `get_group_contents`, `get_movable_children`.
These are imported in the main `Draft.py` module, so compatibility
is retained.
Modules which use these functions are updated; these include
Gui Commands like `Move`, `Rotate`, `Scale`, `AddToGroup`,
as well as objects like `DrawingView` and `Shape2DView`,
and `ViewProviderClone`.
The code inside the `importDXF` module is also updated.
The Arch Workbench uses many of these functions
but it does so from the `Draft` namespace, so these edits
don't change the situation for these commands.
In Python 3 `super()` can be used without an argument
in order to get the parent class, `super()`.
In Python 2 the present class must be used as an argument,
`super(ThisClass, self)`.
This commit is done to support Python 2,
as without it all Gui Command tools will be broken
and will fail to launch, even if the unit tests pass.
Also, set the `__metaclass__` variable to `type`.
This is done to turn all classes into "new style" classes
in Python 2. This is required so `super()` works correctly
in this version of Pyton.
This commit can be reverted once Python 2 support
is completely dropped, and only Python 3 compatible code
is used.
