The gluon-web package is basically a stripped-down and refactored version
of the LuCI base.

As convenient as the Map is, the underlying code is very complex and will
be removed.

To fix the autoupdater.

Add translation support to gluon-status-page, including English, German and Russian translations.

`make list-targets` can be used to discover the available targets in
scripts.

Fixes #1043

In preparation for Babel support.

Remove obsolete x86-xen_domu definition, it has been merged into
x86-generic.

uradvd will tolerate devices appearing and disappearing during runtime.

Also remove our own no_rebroadcast patch, as batman-adv v2016.5 now has a
more sophisticated rebroadcast suppression that should work automatically
in the most relevant cases.

These values have been in use in gluon-core for some time, the validators
need to be moved as well.

macvlan interfaces never directly exchange traffic with the underlying
interface, but only with other hosts behind the interface. In consequence,
router advertisements from the uradvd running on br-client could never
reach local-node, preventing it from getting an IPv6 address without RAs
from an external radvd. Fix this be replacing the macvlan interface with
a veth pair (with the peer interface in br-client).

As a side effect, this saves about 5KB of flash, as the veth module is
simpler than macvlan.