Gnome Paths for opt and var

[Andreas Jellinghaus <aj dungeon inka de>]

my default install point is /opt/gnome.
according to fhs, the etc dir would be /etc/opt/gnome, not /opt/gnome/etc.
according to fhs, the var dir would be /var/opt/gnome, not /opt/gnome/var.

Installing files in /var and /etc : don't overwrite old files, please.
If somebody tuned his config file in /etc, it would be lost.

Installation should behave more like a package manager, with all that care
about config files etc.

andreas