removing the "key-generator" node

[Brian Warner]

Hey, would anybody object if I ripped out the key-generator?

This is a standalone process that does nothing but create RSA keypairs
for people who set key_generator.furl= in their tahoe.cfg . It creates
them in the background so mutable-file creation doesn't need to wait. We
built this back in the AllMyData days because we were worried about how
long clients would block while creating keys, specifically when doing
"tahoe mkdir".

I argued against removing it back in 2008, but I think I've changed my
mind since then. Computers are faster (my home machine creates RSA keys
in 90ms), and there are very few situations where it seems safe or
useful to outsource their key-generation (basically only when both
machines are under your control, but the slower machine is where you run
the tahoe client).

Is anyone using this feature? Would you notice if it just went away?
This would remove the "tahoe create-key-generator" command and
warn/ignore/deprecate the "key_generator.furl=" config setting.

See https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2783 for more details.

thanks,
 -Brian