snap to ways / nodes while in select/move mode

[dieterdreist]

A snap in select/move mode would be great (to move or manipulate existing geometry in a clean way). Snapping ideally should be configurable (on/off in general, snapping to Nodes, Ways, Midpoints).
This would help to move different Objects to the same place without modifying their geometry (e.g. several adjacent tennis-courts: create one in geometry-mode, copy, paste, select complete 2nd one and move corner-point in snap point-mode to corner point of the other).
Another possible use would be to adjust already created orthogonal geometry: greate a rectangle in geometry mode, than adjust length by selecting the nodes of one side and move these nodes *just on* one of the ways -> 90 deg. corners are kept.