Iter::next takes a bool (defaults to true for now) if we want to consume degenerates.

Iter::next takes a bool (defaults to true for now) if we want to consume degenerates.
path-filling and stroking pass false, as they already are written to handle
small segments (and it makes next() run 2x faster if you pass false).
Review URL: https://codereview.appspot.com/6214049

git-svn-id: http://skia.googlecode.com/svn/trunk@3974 2bbb7eff-a529-9590-31e7-b0007b416f81