Incorrectly was dropping spaces when a child tag is present for example

<p><b>THIS IS BOLD, <u>UNDERLINED AND <i>ITALIC</i></u></b></p>
becomes
<p><b>THIS IS BOLD,<u>UNDERLINED AND<i>ITALIC</i></u></b></p>
Merge pull request #581 from mechjagger/master

Don't trim spaces from a nested inline element just because it's parent has no siblings.

This fixes a problem where too much space is trimmed from nested inline elements. It does, however, introduce a deficiency where extraneous space is not collapsed.