Software sources manager suggestion

[Bastien-Boucherat]

In the software sources manager, for the PPA and the additional repository, it would be very helpful to be able to add a label or name to an entry, because the path to repository are very often not self explanatory, and I have hard times knowing what they refer to 5 months later. Especially after upgrading where repositories might not be relevant anymore, but I fear deleting one not knowing for which software/package I added them!