Add support for .iconpack files

[W1zardK1ng]

It would be nice if the iconpack files from AuthenticatorProIcons can be imported and use as icon source since they have huge collection of icons. The current collection of Ageis icon packs misses lots of icons and many are outdated.

[alexbakker]

I don't think we're going to add support for other icon pack formats. It's a little bit unfortunate that the author of Authenticator Pro chose to NIH a new icon pack format, but it is what it is.