bug#12215: Fwd: Re: CSET is unnecessarily confusing

[Paul Eggert]

Thanks, I installed changes to replace all uses of
CSET, BSET, etc. with setter functions, and am marking
this as done.

I left BVAR and FVAR alone for now.  I don't see what
they're used for, though -- they're the same in the
concurrency branch as in the trunk.  And they sometimes
are confusing, too, since they look like functions but
cannot be implemented as functions.