PUT /documents throws error if doc-string has empty spaces

[ezmiller]

The server throws an error if html submitted has a space between tags, like so: <div>1</div> <div>2</div>.

What is happening is that hickory parses the html, and puts a " " where a hiccup node might be. Then the hiccup->arb method throws.

Should handle this error, but it's also something that is unlikely to happen, I think, at least if it's a markdown parser parsing markdown text.