These messages were perhaps originally intended as a debuggin aid but now add clutter to the output panes. Remaining messges are mostly the result of methods to display attributes of an object (which one could call from the Python console) or actually provide some information which would not be obvious from the circumstances
The current make_layer function has a `None` default for the shape color and the line color. With that value the current preference is used. This, and how the function is called, results in some confusing behaviors:
* Newly created layers will only use 2 values from the preferences when they might use 5. The latter makes more sense for the end-user IMO.
* Layers created during DXF import (for example) will have a different shape color depending on the current preferences.
* The make_layer function may reapply colors that have already been set by the view provider.
To solve this all view property related function parameter have been changed to a not None value. If a None value is supplied the view property as set by the view provider is not changed. The Layer Manager has been updated accordingly.
I realize that calling a function with 6 None values is not very convenient, but think it is the solution that is least likely to break other exiting code.
Additionally:
* Removed the makeLayer function. Layers were introduced in V0.19 when the naming scheme was changed to "make_*". Maybe it was created by mistake, or before the actual renaming operation started, but it is safe to remove it now.
* Removed overly verbose messages.
* gui_layers.py had a missing import (result of a previous V0.22 PR): `from draftutils import utils`.
This follows from the migration of the Layer code
done in 831e517717.
In the older `makeLayer` function, the parameters `drawstyle`
and `transparency` could be `None`; in the new `make_layer` function,
`drawstyle` must be an explicit string, and `transparency`
must be a number. If not provided, they use default values.
Move `make_layer` to `draftmake`; `Layer` and `LayerContainer`
to `draftobjects`; `ViewProviderLayer` and `ViewProviderLayerContainer`
to `draftviewproviders`.
The make function and the classes are imported in `Draft.py`
to support the usage of the older `VisGroup`.
