OpenEmbedded "poky" with some sysmocom specific modifications. Mostly used only up to sysmocom release 201310, but the "pyro" branch is still used for 201705
We should use a more recent version of the OpenVPN client. Import
it from the meta-networking layer like we did before. The sysvinit
script has just minor whitespace differences and wasn't imported.
We need to test opkg upgrades of OpenVPN through the VPN. We don't
want to kill the tunnel on such upgrade.