fix for pasting word content with headings between lists

I discovered a bug in the handling of the paste from Word fake lists, where if there was a heading in between multiple lists, the heading was ignored because it wasn't contained in a p tag and so the items from the following list were pulled up into the list above the heading instead of breaking them up properly into multiple lists. This code adds a test case and fix, where instead of only iterating over p tags at the root level of the pasted content, it iterates over all root level nodes.

Here's a sample Word doc: http://1drv.ms/1pTulcD

And here's screenshot of what the test results look like without the fix, which I think probably shows what I mean much more simply than my explanation:
![screen shot 2014-09-11 at 1 51 46 pm](https://cloud.githubusercontent.com/assets/152539/4238885/8c765ca4-39dc-11e4-8d5b-63f9ef542cae.png)