GlideinWMS

When a GWMS service is updated (or reconfigured) it is important to use the latest version of the VO provided scripts.
Currently, operators run git clone commands.
This affects Factory and Frontend
Would be nice for GWMS to provide guidance and a mechanism to ease this:

• a folder where the files are downloaded
• a utility to download the files
• at first operators would edit the configuration. Finally would be nice also if the file section is auto-generated (the attributes would need to be inferred either by a directory tree or the file name or some index file)

Proposed by Edgar, seconded by Brian Lin