Provide placement selection when adding a new section to a page

[jeremyfelt]

On a page with several sections, it would be nice if a new section could be positioned during the process of adding it rather than having it appear at the bottom every time. The process of dragging the section up through existing sections can be irritating when many sections exist already.

A modal could appear with a list of the existing selections and allow you to choose which to insert the section before/after.