Fix : CDN fontawesome + warning no configfolder

[Matth-L]

Hello,

In PR #16, I forgot to include the Font Awesome CDN. Jureptool should now have an alternative for all JS libraries.

Moreover, I added a warning message that is shown when no config folder is provided and the default one is used (which is related to JURI).

[filipesmg]

I'm not sure how this PR will work together with PR#17, since there you also included some of the changes here. I'll accept that one first, and then I see how this one will work.

[filipesmg]

Ok, seems to work fine. I have also pushed some internal commit that I had done in the last days. I may have done something wrong, as git is giving me some weird messages, but it seems to work anyway.

About this PR, I have mixed feelings about both things here: adding the Warning log (which may be annoying if someone is running by hand) and another option for the standalone_link (which is another option in the configuration for people to understand, which I always try to avoid), but I see that they may be useful and I don't have any better suggestions. So I'll accept and merge the PR and we can always think on improvements later.