Changes to compute zeta to deal with fix #72
Cleaned up some comments in radiation
Cleaned up zeta.c, relates to #72
commented out GS log statement
Converted frequencies to rest frame of cell in radiation.c
Added some comments
Merge pull request #74 from jhmatthews/freq_hotfix

Fix for Bug #73. Now use frequency shifted to frame of cell then averaged
Added levelpopulation option for macro atoms to py_wind for each cell for tests
Merge branch 'dev' of https://github.com/agnwinds/python into dev
Added errors for -ve rates, moved macro_pops call out of elements loop
Added test to check that populations are solution to rate matrix equation in macro_pops
Added a comment describing change;
Merge pull request #75 from jhmatthews/dev

More robust errors and checking of populations in macro_pops
added flag to only clean populations if levels are radiatively linked
commented changes
Merge pull request #76 from jhmatthews/dev

Only clean for population inversions if levels have a radiative transition between them
Merge branch 'dev' into nwaves