ots and diffuse rates are fundamentally different since ots must be
constantly updated as the solution progresses, but diffuse needed only
once per zone
so they are done in two different sets of routines

ots rates for he, heavier elements, done in RT_OTS.c
ots rates for hydrogenic sequence in HydroOTS

diffuse, outward continua for all species done in  RTDiffuse

add otslines

hydrogen lines

level1 lines

level2 lines

forbidden lines

===================================================

RTMakeStat and RTMakeWind call escape prob routines, set pumping, etc.

escape probabilities are in rtescprob.

===================================================

optical depths originally estimated in RTOptDepthInit
optical depths are incremented in RTOptDepthIncre
at end of iteration optical depth scale is reset in RTOptDepthReset (in rtoptdepthinit.c)

