Feature request: optional snap to objects that don't appear in this view

[joehrlein]

A feature working like "disable snapping for a layer" but the other way round would be nice. Snapping to inactive layers would allow to generate auxiliary layers.

Thank you!

[joehrlein]

The way I use ipe, it would also be reasonable to combine this feature with an "always on top"-option.
This could result in a layer class "auxiliary" with the following properties:

• it is always possible to snap to its objects no matter whether they are visible
• its objects are "always on top", i.e. above all objects of regular/non-auxiliary layers
• the layer is only visible in ipe no matter whether its active or inactive (maybe)
• the layer is availabe on every page (maybe; if this is possible; and maybe optional...)