ShellAppSystem: handle desktop files with capital letters

This is needed to handle applications that are converted to
reverse dns notation, if their application ID includes capital
letters (as it is often the case for DBus names)

https://bugzilla.gnome.org/show_bug.cgi?id=706252
ShellWindowTracker: support looking apps from GApplication IDs

In the new application model, there is one ID shared by GApplication,
DBus and .desktop files, so we can use that for the association,
instead of fiddling with badly cased wm classes.

https://bugzilla.gnome.org/show_bug.cgi?id=706252
network: fix iterating connections in NMConnectionSection

Must compare the length of the array, not the array itself.

https://bugzilla.gnome.org/show_bug.cgi?id=706262