Change to zstd compressed instead of gz-compressed tarballs. zstd
compresses 7-8 times faster and decompresses 2-3 times faster.
This change also make sharing tarballs between different branches
possible, because OpenWrt 25.12 uses zstd as default.
Signed-off-by: Andreas Gnau <andreas.gnau@iopsys.eu>
* sshmngr uci is deprecated and so are the library functions
related to managing that uci, sshmngr will directly interact
with the backend uci now
* a compile time flag is introduced which tells sshmngr code
whether dropbear backend is being used or not
Make the backend daemon configurable, please note, still need
to disable dropbear as default in config and choose the backend
based on config in sshmngr
