feature request: midpoint snap for arches/curves

 From:  Michael Gibson
485.3 In reply to 485.1 
Yeah, at the moment Pilou's method of using a construction line to find it should work.

But I should be able to pretty easily put a mid snap in there as well, just another thing that's on the list that I haven't got around to yet. On my list I had it bundled with doing a mid snap on any arbitrary curve which is a bit more difficult. Just doing it for arcs is a lot easier so I should be able to add that part in for the next beta.

- Michael