stop attempts to display major buildings on z10 z11, special display across all levels

even the largest building in the world by footprint would be barely visible on z10 z11 so old building_major layer was not useful
now major buildings (place_of_worship for start) are displayed specially across all zoom levels with visible buildings
separate layer is necessary to ensure that building line of major building will be rendered on top of building line of touching building
note that major buildings will be rendered on top of not major buildings, including major buildings with lower layer tag
note that now aeroway terminal without building tag now will not be displayed

![selection_002](https://cloud.githubusercontent.com/assets/899988/4741651/61f6b5ee-5a18-11e4-93ea-06f0c1e71623.png)