shading:

This folder contains test cases pretaining to ESP-r's shading 
algorithms:

 - obs_4_eachface.cfg: This model contains four obstructions shading 
      glazing on each side of the building. The geometry is unique 
      in that the edge list for each wall begins from the bottom-right 
      corner as viewed from the outside (whereas prj-generated 
      geometry starts fromt the bottom-left corner.) This geometry
      exposed an ish bug that was patched here:

      https://node9.cvsdude.com/trac/espr/esp-r/changeset/3367
