Pybdshadow

- update `get_buildings.py` add function `get_buildings_by_polygon` and `get_buildings_by_bounds`
- update `facade.py` which is able to calculate facade shadow and sunshine

fix bug
- use azimuthal equidistant projection instead of mercator

add vector calculation in `cal_sunshine`

fix bug in point light calculation

Add `cal_sunshine`

Add `analysis` functions