Refs #3697 Prettify ISP names

A first implementation of the new feature requested in #3697.
It might be better to export the array of ISP names in a separate file (in the core/DataFiles folder, as it's done for search engines or countries for example), what do you think about it?

Note that I'm the same person as "bugmenot" (the author of the ticket), but with a new github account and my real name this time ;-)