Bug#877424: Cleanup iPhone manual and prepare for stretch

Package: wiki.debian.org

Please update https://wiki.debian.org/iPhone .

As of today, this manual has nothing to offer for Debian stretch 9.1 and 
iOS 11.0.1. The various solutions for older combinations fail for me. 
Even worse, this manual seems to be in a raw, cluttered state even for 
older Debian versions. Please test and update with at least one working 
scenario for this combination.

Ideally, this manual should let the user choose his/her Debian version, 
his/her iOS version, and direct him/her to the corresponding howto.

Thanks in advance,
Leon