Remove the defunct City::display_map().  Add a bool parameter to City::draw_map() which, if true, means we don't display areas (only terrain).  In City::get_map_info(), color the name of the area (if any) pink to make it stand out.
bool Interface::show_terrain tracks whether or not to only draw terrain in our map (if false, we also draw areas).
Slight overhaul of the main interface.  Fields renamed, some info moved to different parts of the screen.  Use Interface::show_terrain in city->draw_map() to decide whether to only draw terrain.  In Interface::display_area_stats(), put map-related info at the top and city-related info at the bottom.
Colorize output of Map_tile::get_info().
Add a level to trees_amount_ranking().