omitClose for all void elements

According to http://www.w3.org/TR/html5/syntax.html#void-elements the following elements should not specify end tags:

area, base, br, col, embed, hr, img, input, keygen, link, meta, param, source, track, wbr
Merge pull request #1181 from lrowe/patch-5

omitClose for all void elements
Community Round-up #18