Adds new file headers to gBergMag
Adds baseline WdAtmosphereModels with new high-res bergeron models
Makes the new bergeron models compile

Included updates to the Model loading process, changes DA vs. DB to an enum class, and adds a enum class for atmosphere type.

This compiles, but probably doesn't work.
Makes the H/He split code in Bergeron handle the end of files properly
Fixes linear transformation in new bergeron models
Merge branch 'new_bergeron' into develop