Differences between inputs for AGN and other systems

[kslong]

Although we have made efforts to make the central object keywords similar, there are different options for central objects in stars and AGN. This is, at root, because a lot of the code for setting up an AGN is seperate from stars. This leads to problems, and should be fixed.

A specific issue however is that whereas one can read in an SED for an AGN, one cannot simply read in and SED for a "star". This should be fixed. (It can be done without addressing the larger problem, but it is an example of the issues the larger problem causes).

Furthermore since one does not normally have both a star and an AGN in a system there are simplifications that should be made by eliminating PTYPES that involve the origin of a photon. (All of this is historical, but if it were fixed, it would make code maintenance simpler.