kiwisdr support

[totoCZ]

kiwisdr support would be ideal for the NA stations but there are a few blockers

• no server-side squelch (client would need to measure signal level)
• SND protocol needs to be implemented

.. wishlist

[totoCZ]

oj kurva mechanizm

https://github.com/jks-prv/kiwiclient/blob/master/kiwirecorder.py native client

• investigate squelch support https://github.com/jks-prv/kiwiclient/commit/e9e0fd1991dca70da52b099f058660e009e51a78
• work on prototype integration

how awesome is it now that we're always forking a whole new process for the grabber :-)