Divide preferences by section in the admin interface - Signals problem

[CapAlex94]

Hi, first of all congratulations for the excellent extension!

I'm using the global_preference for different configurations inside my app, using the admin interface to allow users to update the configurations. I'm currently using 2 different section to define configurations. I would like to divide the "GLOBAL PREFERENCE" block by section in order to make more easily to update preferences of a specific section.

What i would like to create is something like the following structure:

global preferences | |_ Section 1 |_ Conf 1 |_ Conf 2 | |_ Section 2 |_ Conf 1 |_ Conf 2

How can I create this structure inside the admin interface?

Second problem:

I'm trying to use signals to perform action when a preference is updated. At the moment, I'm following the documentation and I have create the callback function inside an utils.py file and I have registered the signal receiver inside the apps.py file inside one of the application of my Django project. I have updated one of the preference available using the admin interface but my callback function is not called. Is that normal or I am missing something?

Thanks for the support!!