Changes:
1. Added support for multiple profiles and profile inheritance (no need to have multiple copies of wifibroadcast.cfg).
2. No hadcoded streams (video/mavlink/tunnel) anymore. You can define own profiles and any number of data streams can be added/removed to profiles without any code change.
3. Multiple profiles can be active simultaneously (no need to run multiple instances of wfb-server when using the same wifi adapters for different links).
4. Added support for raw udp data streams. They don't use any frame aggregation or mavlink injection.
5. TX antenna selection is now link_domain wide - i.e. one-way udp_proxy tx stream will use active antenna selected by other RX streams.
Compatibility:
This commit maintain both radio and config compatibility with previous version.
So you can use previous verion of wfb-ng on the other link side and import most of your customizations from /etc/wifibroadcast.cfg
The only config incompatible change is that `common.link_id` was moved to profile section and renamed to `link_domain`.
1. Add option for socket buffer size for incoming messages on the tx side.
2. Check for socket buffer overflow and show warnings.
You can set socket buffer size system-wide via net.core.rmem_default or
via -R option in wfb_tx.
Now it is possible to use backup link via LTE modem or connect onboard computer without external mavlink-router.
To connect as backup link in QGC use tcp connection to port 5760 and check "high latency link" checkbox.
