generate new photometry

[karllark]

need to be able to generate new photometry from an input filter response function

[jchastenet]

Code for new photometry is written. Improvements:

• speed; very slow for now, probably ways to speed it up
• add the blackbody function for integration (when reference isn't nu/nu_0)
• "save" the cube sometimes, in case everything crashes

[karllark]

Great. More work is needed and hopefully one of us will enhance the code.