appliance: exclude /usr/share/fonts and /usr/share/icons.

I also sorted the list.

Between libguestfs 1.28 and 1.30, the appliance grew from 95MB to 213MB.

Using guestmount and filelight (see link below) I could see that the
main contributor was these two directories, which should not be
necessary.

With this change, the size goes down to 119MB.

See also:
https://rwmj.wordpress.com/2015/07/23/why-has-the-libguestfs-appliance-grown-by-118-mb/

appliance/excludefiles.in

@@ -23,13 +23,15 @@ dnl The right kernel modules are added back by supermin.
 -/lib/modules/*
 
 -/usr/lib/locale/*
+-/usr/share/cracklib/*
+-/usr/share/doc/*
+-/usr/share/fonts/*
+-/usr/share/gnome/help/*
+-/usr/share/i18n/*
+-/usr/share/icons/*
+-/usr/share/info/*
 -/usr/share/locale/*
 -/usr/share/man/*
--/usr/share/doc/*
--/usr/share/info/*
--/usr/share/gnome/help/*
--/usr/share/cracklib/*
--/usr/share/i18n/*
 -/usr/share/pkgconfig/*
 
 -/var/log/?tmp