f452606020
Rename libnm's NMVpnPlugin to NMVpnPluginOld, in preparation for having a new-and-improved NMVpnPlugin in NM 1.2. Also remove it from NM-1.0.gir. Make nm-vpn-plugin-old.h be separately includable, since it's not included from NetworkManager.h, and we probably don't want it to be. Remove NMVpnPlugin, NMVpnPluginUiInterface, and nm-vpn-plugin-utils from the docs, since they're basically undocumented anyway.
