[HEADSUP] recent instability on ports for 4.X

[Mark Linimon]

The most recent checkin of bsd.*.mk has caused some instability which we
(the portmgr team) now think we've fixed the critical parts of.  'make
search' is still broken and we are working on that.  This only affects 4.X.

This was the first time we've tested a patchset on 5-exp instead of 4-exp
and of course this enraged Murphy (he of Murphy's Law) and so he came and
bit us pretty hard.

As well, a few ports that were doing non-standard things with USE_RC_SUBR
were broken by this same checkin, and we are working with the maintainers
on those ports as we find them.

Apologies for the instability.

mcl