remove lib/document

would you consider refactoring the code so that min-document is only used in the tests?

from what i can tell, this has 3 main parts for virtual-dom
* updating render to remove `require('./lib/document')`
* updating the tests to automatically pass `opts.document`
* updating patch-op to pass `opts.document` (`parentNode.ownerDocument` or `domNode.ownerDocument`)

...and min-document would need to add support for `ownerDocument` on it's nodes.

i wanted to see what you think before i go to the effort