Use offline maps

[dernasherbrezon]

Currently google maps are required to render airplane positions.

Expected:

• use openstreetmap
• use world map
• remove unnecessary detalization, like streets and routes. i.e. determine what is the minimal zoom for airplanes (as they definitely fly on lower altitudes than satellites) (http://www.openstreetmap.org/user/robbieonsea/diary/41933)
• create .deb package with result tiles. (shouldnt take much space).
• extract tiles into the nginx accessible directory
• configure this directory in nginx
• use leafletjs (http://leafletjs.com/) to render tiles