Speedy join only works when the received packet is either broadcast or an
4addr unicast packet. Thus packets converted from broadcast to unicast via
the gateway handling code have to be converted to 4addr packets to allow
the receiving gateway server to add the sender address as temporary entry
to the translation table.

Not doing it will make the batman-adv gateway server drop the DHCP response
in many situations because it doesn't yet have the TT entry for the
destination of the DHCP response.

Signed-off-by: Sven Eckelmann <sven@narfation.org>

batman-adv & alfred 2016.2.

Now really fixes the build on Debian Jessie...

Allow to build Gluon with GCC 4.7 (e.g. on Debian Wheezy) as host compiler
again.

Make pkg-config, mkimage and gcc build with GCC 6 as host compiler. Fix
miscompilation of node.

Fixes #755

Should be redundant after 0bd0df6f

LuCI's authentication won't work without rpcd, but we aren't using the
authentication anyways. Users who need it can just install rpcd explicitly.

Fixes #452

Apart from replacing a patch for the former by two patches for latter,
this involved minimal adaptations of the lua scripts in the following
packages:

* gluon-announce
* gluon-announced
* gluon-mesh-batman-adv-core
* gluon-status-page

This also updates batman-adv & alfred to 2015.1

This should workaround batman-adv's inability to deal with different MTUs
which need fragmentation.

Fixes #435