fixing mobile map + other minor mobile adjustments.
fix overflow on login page on mobile.
Merge branch 'master' of git://github.com/openstreetmap/openstreetmap-website
Merge branch 'master' of git://github.com/openstreetmap/openstreetmap-website
Merge branch 'master' of git://github.com/openstreetmap/openstreetmap-website
Merge branch 'master' of git://github.com/openstreetmap/openstreetmap-website
Merge branch 'master' of git://github.com/openstreetmap/openstreetmap-website
Merge branch 'map-ui' of github.com:osmlab/openstreetmap-website into map-ui
adding icons to sprite.