Fixes T3633

Setup Ipsec VPN on Fritzbox 7530 and connect from outside using PSK-XAUTH (only supported option in AVM products). Accessed multiple different Network devices and some internet sites through vpn.

Unfortunately curl cannot download original Sourcecode from https://www.unix-ag.uni-kl.de/~massar/vpnc/ due to certificate error "SSL certificate problem: unable to get local issuer certificate" (propably the website is missing some intermediate certificate in its cert chain). Therfor I switched to an ubuntu archive and verified that it matches the latest svn revision from original source.