[Safari] Range.enlarge test failing in Safari 7.0

[Olek Nowodziński]

Test /dt/core/dom/range/enlarge.html#test_enlarge_element12 fails in latest Safari 7.0 that comes with OSX 10.9.

The root of the problem is the following condition: ​https://github.com/ckeditor/ckeditor-dev/blob/major/core/dom/range.js#L1039

In this case sibling is empty <b></b> (<p>Test <i><b></b>[Enlarge]</i></p>). Unlike previous versions, Safari 7 considers sibling.$.offsetWidth to be 1 at that point, while in other browsers it is 0. So the conclusion is that empty elements may have some width, which seems to be a regression in browser's engine.

That particular test fails since CKeditor 4.0 in Safari 7 which makes it clear that we're facing Safari regression.