+ improved setup with index macros

decide whether to prefer \partial or \d).

propagation.

real for the case of a vacuum top layer) is not a choice but results
from continuity conditions.
Also lots of additions to the index.

longer contained in the refractive index.

Make definition of \v (bold math vector) conditional on unicode-math version. This should close Bug #1293.

Form factor table now with proposed new names.