Bug#860796: Now have a working Destkop

[Ben Green]

Today I decided to clean out my system as best I could and see if the  
problem still persisted.

I ran:

apt-get --purge remove `apt-show-versions  | grep -v uptodate$ | grep  
-v "not installed$" | awk -F: '{print $1}'`

then repeated ran:

apt-get --purge remove `deborphan`
apt-get --purge autoremove

Until no more packages were removed. I then for some reason needed to  
re-install the 'gnome' metapackage. Desktop icons now function  
normally, opening a nautilus window when double clicked.

I was not aware of there being any libraries or packages installed  
from anything other than 'stretch', a list of packages is at the head  
of this ticket, however something has clearly changed and the system  
now works.

Cheers,
Ben