The overlay was responsible for script loading and defining three elements
(bhTooltip, placesCommands, placesContext). In the majority of places where
the overlay was included only part of it was used. To remove the overlay, the
elements were each split into include files and moved into where they
were used. For the scripts, a JS file was added that defines all the lazy
modules and then this script, globalOverlay.js and utilityOverlay.js were
inlined to everywhere that would have included them from the overlay.
MozReview-Commit-ID: 8T5D46oYWLn
