Fixed info box to hide when not over map.

Also avoid overflowign the page when outside the canvas.
And some visual tweaks (fade effects, rounded corner).
minor tweaks
Merge branch 'master' of public.kitware.com:OpenGeoscience/geoweb into 86-lat-lon-hover-text
Layers now report the scalar values when queried
merged master in
only visual cleanup
merged 86-lat-lon-hover-text into next