Fixes for the edit help popup link:

Fixes for the edit help popup link:
* Now works w/ JavaScript disabled
* Doesn't override window chrome to make things unusable
* Doesn't hardcode window dimensions
* Notifies the user that it'll be a popup (new msg 'newwindow')

(The link is a popup because IE and perhaps other browsers will destroy
the edited page text if you go to another page then hit 'back'.)