got fixed map background showing, based on leaflet and openstreetmap
pull out MapBackground class
got it showing map backgrounds which are mostly correct; I am not convinced it is exactly correct
added rect for bounds which shows, as expected, that it does not match up; this is not too surprising since geohashes change between landscape and portrait aspect as you get smaller
started some mad hacks by applying transforms to background leaflet div to scale it to screen
added translations as well; not yet working properly
more debugging of scaling
more playing with transforms, trying to understand how they work
more trying to understand transforms
Merge branch 'map-bg'
bump up version
Merge branch 'map-bg'
do not show zoom controls as they are not useful
add reference map
add a second reference map
fit maps to "gc" geohash bounds
show bounds as a rectangle
apply no-op transform to map2
added scaling, appears to be working
applied scaling back to main MapBackground: the fix that I was missing is that I did not need *any* translation, as fitBounds always seems to show rect in centre of screen, which makes sense