Support having version-specific lxc-config as conf/${DISTRIBUTION}-${RELEASE}
Support having version-specific lxc-config as conf/${DISTRIBUTION}-${RELEASE}

if present, this is used, otherwise conf/${DISTRIBUTION} as before.

DavBfr/vagrant-lxc-base-boxes,obnoxxx/vagrant-lxc-base-boxes,sephii/vagrant-lxc-base-boxes,DavBfr/vagrant-lxc-base-boxes