Disable Grouper adds for undergrads

[astrochun]

Undergrads will by default have a quota of zero. Only those with privileges are manually added using the user_update script. Thus an option should be added to disable running it the ugrad quota.

Options are:

1. Change the figshare.ini
2. Add an option to warn of not running in the logs and execute other groups as is. For the latter, this means that the number of members satisfying the EDS query is known.

I will implement this in feature/limited_set