Provide mechanism for inline insertion *before* xPath expression

It would be nice to be able to insert content before the xPath expression's result element.

Proposal: Add a checkbox to the inline element insertion's xPath expression:

[ ] Insert before found element

Which defaults to unchecked.

If this checkbox is checked, the insertion will take place before the insertion point resulting from the given xPath expression. This will allow insertion at top/bottom of the node body using xPath (thus making the top/bottom insertion templates redundant, or, they could be implemented using xPath internally.)