Skip non-widgets in _Container._getSiblingOfChild(). Fixes #4948: editor: addition of comboBox into editor toolbar breaks keyboard a11y for toolbar.
Skip non-widgets in _Container._getSiblingOfChild(). Fixes #4948: editor: addition of comboBox into editor toolbar breaks keyboard a11y for toolbar.

git-svn-id: 674a2d6b1e32e53f607eb824547723f32280967e@11279 560b804f-0ae3-0310-86f3-f6aa0a117693

redaktor/deliteful