refactor to remove fabrium_id (instead offset the pk id)
fabrics: add weight
fabrics: add width
fabrics: add initial properties spec
add basic mill model
fabrics calc/store distinct weights (gsm, glm, osy)

This is necessary because glm is a function of the fabric's width, and
the search interface searches by unit only (glm between x and y)
fabrics: add country
fabrics: misc fields
add future gems
fabric variants
reorganized js assets
basics of rgb->lab, angular goofing about