Finished styling all roads in zoom level 13

Also made highway=trunk roads to be with same width as highway=motorway on
all zoom levels
Made residential roads to be quite small width in zoom level 13
Made highway_steps to appear only from zoom level 17
Made highway_track to appear only from zoom level 16
Made highway_service to appear only from zoom level 14
Changes with buildings appearance

Made all buildings to appear from zoom level 14
Removed symbol gate2.png