Fix zeroing error of variable xilevt in func.

Modifications which allow the use of data files from version 2.0 and 2.1xx.

Updates to atomic database to include R-matrix calculations for nitrogen.

More accurate evaluation of voigt function (greater wavelength range)for line absorption.

Fixes to invert.f to allow iterative runs.

Include lte level population in fits output files.

Force evaluation of photoionization integrals even when heating sum stops changing. Include smaller Boltzmann factors in milne sum.

Include printout of local blackbody in opacity printout (lprint=2).

Fixed sign error in spline routine used by Burgess Tully routine.

More accurate evaluation of Planck function.

Tim Kallman 2018-07-13