Freeze break request for gvfs (iOS support)

[Bastien Nocera <hadess hadess net>]

These patches:
https://bugzilla.gnome.org/show_bug.cgi?id=763606
fix regressions accessing files on recent iOS versions.

I tested the fixes, and will cherry pick them to older versions of gvfs
as well.

I should note though, that I seem to be the only person using this
functionality[1], at least recently, so if I have free reign for this
piece of code, I'd like to also commit some other fixes[2] I have for
the iOS support. Ondrej seems to be happy letting me handle this, as he
doesn't have hardware to test it.

Cheers

[1]: If gvfs doesn't work, technically minded folks will use ifuse,
which does pretty much the same job
[2]: https://bugzilla.gnome.org/show_bug.cgi?id=749639