ASDF 3.1.7.43 is 3.2 release candidate

[Robert Goldman]

Per Daniel's request, I have tested and merged the link-objects-only
merge request, and the result is ASDF 3.1.7.43

At this point, I'm done with anything except patches that we discover in
pre-release testing, writing the changelog, etc.

Will everyone who can please try out the latest ASDF with their own
systems?  And Anton, if you could test it with the cl-test-grid, that
would be great.

I'd like to push this out by the end of next week.

I'm considering bumping the version on this to 3.2.0 so that anyone who
wants to test new features with conditionalization on ASDF version can
try it out.  Any objections?

Best,
r