Move snapping setting to global lavel (instead of per document property)

It should be possible to put your preferred snap settings in the default new document template, if I'm right. Never tested this though. At least this gives you a default set of settings for each new document.

In general though I think though that snapping settings should be stored per document, not globally.

> It should be possible to put your preferred snap settings in the default
> new document template, if I'm right. Never tested this though.

Tested and confirmed: snap settings are picked up from the used template. You can either edit the global default template ('/usr/share/inkscape/templates/default.svg') or save a user default template as '~/.config/inkscape/templates/default.svg' - it will set document-specific settings like window size, page size, initial zoom level&center, guides, grids, snapping (what snaps, snap targets) etc. for each new document.

<http://bazaar.launchpad.net/~inkscape.dev/inkscape/trunk/annotate/head%3A/share/templates/README>

It's nice to know how "defaults" work, but it's just a workaround. I'd rather try to do it right.
That right way IMHO is:
- predefined defaults in preferences
- per document saved settings
in that order.

related earlier discussion:
Bug #246028 “Why snapping is in document properties”:
<https://bugs.launchpad.net/inkscape/+bug/246028>