Fix querySelectorAll() on unparented Elements.

This removed code dated back to when domino used Sizzle as its selector
implementation.  It caused the first querySelectorAll() on an unparented
Element to parent the node and then run the query on the parent node,
with surprising results.
Merge pull request #23 from cscott/qsa-orphan

Fix querySelectorAll() on unparented Elements.