layer editing icon doesn't show on layers loaded from a project

[smizuno]

For items on Layers panel: with the recent return of indicating that a layer is being edited, which works on layers added to a project, editing is not indicated for layers loaded from a project file.

Also, the layer items bounce a bit because the edit icon is a different size from the layer type icon, which is a minor annoyance. Perhaps the editing icon could be overlaid on the type icon, which is how it used to be.

These were observed on Windows XP, but I believe all platforms are affected.

[lutra]

Hi,

this is duplicate of #1760, that I confirmed under Linux, so now we know it is a issue on probably all platforms.