FIX: HTML blocks should not be surrounded by <p>

[eviltrout]

Part of the Markdown spec specifies that if html tags are present in their own block they should not be surrounded by paragraphs. This patch checks to see if a block begins with an HTML tag before surrounding it in a paragraph.

A secondary part changes the debugging method to not complain if the JsonML fragment that comes back is a string. I suppose previously everything had a tag around it!

[ashb]

This is a much bigger issue than this looks at first and there are 3 other pull requests that deal with inline HTML: #98, #87, #34 (and an issue #16)

Also There's things like if the element starts with a block level HTML element then markdown is not processed in it. Compare the various cases in this babelmark

So I'm going to close this pull request as HTML support is a whole other can of worms more than just this commit.

(My personal view on inline HTML in markdown is that it goes against using a plain text format but it is in the spec so we should support it. Somehow)