GnuPG cryptographic defaults on the 2.2 branch

[Robert J. Hansen]

> I am merely asking for more safety
> margin, which comes at little to no cost.

And the proper response to this is, "absolutely not".  *Why* we add more
margin is as important as the margin itself.

There are some very good justifications to move to RSA-3072:

	* Compliance with NIST guidance
	* Raising the minimum estimated work factor to 2**127
	* User demand
	* Etc., etc.

But "it costs very little to get more margin", when our margin is
already a factor of a *billion* stronger than it needs to be, is just a
nonstarter.  If a billion isn't enough for you, then what is?