Don't assume a single character has a single bounding rect
Don't assume a single character has a single bounding rect

(Since soft breaks have two.)

Issue #322

tzuhsiulin/prosemirror,tzuhsiulin/prosemirror,salzhrani/prosemirror,tzuhsiulin/prosemirror,kiejo/prosemirror,salzhrani/prosemirror,kiejo/prosemirror,kiejo/prosemirror,salzhrani/prosemirror