Model Creator: Modifers not created

[JoschD]

A modifiers.madx file is assumed, when loading model from directory,
but this file is never written out by the creator.
Instead the path to the modifiers is inserted into the job.madx.

Also there is no problem allowing multiple modifier files.

possible solutions:

• read modifier files from job.madx by a common tag
• create modifiers.madx file and read modifiers from there.

[JoschD]

Went with the first one (job.create_model.madx) with modifier tag !@modifier, as created by model creator. But if not present also checks for modifiers.madx in folder.