Add comparator for .nib files (NIBArchive)

.nib are binary files common in IOS apps which startswith "NIBArchive", file return "data" on them, thus binary diff shown for them.

I found only the following tool for linux to parse them: https://github.com/davidquesada/ibtool

by calling (it require python2, was successfully run on attached 3 different .nib files) python ibtool.py -e --dump filename.nib

runtime.nib objects-13.0+.nib LaunchScreen.nib