Backend returns all shading as strings

This fixes shading not appearing for standard room shapes.
Strings for bgpath

The backend returns strings for bgpath.  Updated spec.json to
match the backend behavior.
Changed shading paths to hash

housing.style.bgpath now uses the hash housing.style.paths instead
of a switch statement.  This is much more efficient.
Merge pull request #43 from RITHonorsTechCommittee/shading-and-backend

Shading bgpath strings work with backend