Adds support for Alfa AP121F USB powered travel router (looks like an USB ethernet adapter).
There is no factory image, but only a sysupgrade file for this router which can be installed using the inbuilt UBoot web interface.
Configure your PC with IP address 192.168.1.2 and connect the router using its RJ45 port. Hold the reset button while powering the device until all LEDs have flashed 3 times simultaneously. You can now access the fallback web interface using a web browser at http://192.168.1.1 and flash the sysupgrade file.

gluon-config-mode-contact-info: provide enhancements for german, english and french translation to comply with DSGVO (#1394)

* do not allow to obligatorily require contact information
* add remark that the data is provided voluntarily
* mention how to delete the data
* be very clear about the fact that the data being entered is public and
  can be downloaded and processed by anyone.

based on package documentation, authored by T_X 
https://github.com/freifunk-gluon/gluon/blob/84a6f65f02d7e36a073ba2839712f0c0bb1dda10/package/gluon-ebtables-limit-arp/Makefile#L18-L39

fixes #1383

In multidomain setups, VXLAN is enabled by default, but can be disabled in
domain configs using the mesh/vxlan option. In single domain setups, the
mesh/vxlan option is mandatory.

The UCI option for legacy mode is removed.

Fixes #1364

dnsmasq's caching is severly broken and does not handle all answer records
equally. In particular, its cached answers are missing DNSKEY and DS
records, breaking DNSSEC validation on clients.

Remove the cache for now. It may return if dnsmasq is fixed or we switch to
a different resolver.

At the moment, we don't have a good guideline for package-specific
configuration, but it seems like a good idea not to split configuration
into too many tiny pages, especially for packages that aren't commonly
selected explicitly.

Some uncommon configuration is dropped from the example site.conf to remove
clutter.

This setting allows to enforce manually setting a hostname.

In the initial configuration, the hostname field is now left empty; when
setting the hostname is not enforced, the default hostname is shown as the
field placeholder.

Fixes #1139

Also add documentation about config mode settings.

We must ensure that each node becomes IGMP/MLD querier for its local
clients; having only a single querier for the whole mesh is generally
unreliable, leading to frequent "IGMP/MLD querier appeared/disappeared"
messages from batman-adv and unreliable snooping.

In smaller meshes it might be interesting only segment querier domains, but
allow membership reports to pass through the mesh, in order to support
snooping switches outside the mesh without special configuration. A
site.conf switch is provided to control this behaviour.

Fixes #1320

* change type of next_node.name
* create domain entry for each entry and add to dnsmasq configuration

[Matthias Schiffer: reword documentation]