Updating INSTALL.opensuse file with the changes by Freek de Kruijf

Freek de Kruijf (from @opensuse.org) has adapted the installation
guide (that I - Ricardo Dias Marques - had created) about installing
"Koha 3.0.0 in openSUSE 11.0" and he kindly updated it with the
information about installing the same version of Koha (3.0.0),
but on a more recent version of openSUSE (openSUSE 11.3 instead
of openSUSE 11.0).

He also has put his version on the Koha Wiki:

Koha 3.0.0 on openSUSE 11.3
http://wiki.koha-community.org/wiki/Koha_3.0.0_on_openSUSE_11.3

This commit updates the INSTALL.opensuse to have the content of
that wiki page (last modified on 16-Oct-2010), changing only
things that are related to converting the format from a wiki
page to text format (replacing some HTML tags by some markers
and replacing screenshots by their descriptions).

This commit may be applied to the "master" branch and it can
also be "cherry-picked" to the "3.2.x" branch.

Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>