Imported Upstream version 2.1.8
Merge tag 'upstream/2.1.8'

Upstream version 2.1.8
Update patches for 2.1.8
Update menu configuration for new logo
Point watch to new gnome.org download location
Install some documentation from the tarball
Update copyright for gnome.org download location
Update rules to call included autogen.sh
Add and update Build-Depends
Update debian/changelog