.gitignore
Take only a const AtmosphericMixture to PhotonEvaluator
Missing accessor
This needs to not be const for the current design

This needs to be fixed because it will break thread safety
Fix contruction order warnings
Compile time bug fixes
Objects not pointers
Missing destructor
Feed const objects to Evaluators

Evaluator compiling now. Need to now redo test to use evaluator then
pull out the now redundant stuff from the helper.