Add reporting of UI version to basic push-peer-info set.

If a GUIs sets IV_OPENVPN_GUI_VERSION the version will be pushed to the
server.

Usage convention for IV_OPENVPN_GUI_VERSION is "<gui_id><space><version>",
for example "de.blinkt.openvpn 0.5.47" for the ICS Android version.

Signed-off-by: Arne Schwabe <arne@rfc2549.org>
Acked-by: Gert Doering <gert@greenie.muc.de>
Acked-by: James Yonan <james@openvpn.net>
Message-Id: <1370005175-14871-1-git-send-email-arne@rfc2549.org>
URL: http://article.gmane.org/gmane.network.openvpn.devel/7646
Signed-off-by: Gert Doering <gert@greenie.muc.de>
(cherry picked from commit f3a2cd255a3bc73a546a5e2d09fa30a16cce0d7d)