Namespace cookies

[sigaloid]

I think this should also alleviate the issue of colliding cookie variables. For example, if you're running both redlib and searxng on the same host, they'll both overwrite each other's theme cookie. At best you're stuck with the default system theme on redlib and at worst, a "corrupted preferences" on searxing.

Originally posted by @gnatbandanna in #64

Didn't think about this, but since cookies aren't distinguished by port.. we should probably preface every cookie with redlib_ and handle the migration regarding that.