implemented definitions for ion modes in python.h and relevant routines for ionization
Switched TE and TR numbers, also corrected one omission
fixed version.h conflict
Merge branch 'dev' of https://github.com/agnwinds/python into ion_modes
Set LTE mode to use T_r, and used definitions in levels.c and partition.c
Merge pull request #87 from jhmatthews/ion_modes

# definitions, rather than numbers, for ion and nebular modes