link reflmodule as c++ on os x
delay load reflmodule so doc build doesn't require compiler
remove debug noise
update installation docs
doc twiddle
doc link fixup; use TeX markup for polymer math
release R0.7.7
doc tweaks
document release process (such as it is)
New sld method

Adding the slabs argument allows universal application of an sld method
to any mixture of materials. Caching the result avoids duplicate
computation since the profile function is expensive.

This modification was pervasive. Is there a way to get Pz, Pw globally
without calling slabs.microslabs(thickness)?