pkg on old current - library woes

Hi list,

I'm writing this as an reminder for others who might be in a similar
situation. Don't blindly (like me) use pkg on an old current or you'll
(understandably) run into tons of library / linking issues.

I update my current only very belatedly and thus was running current
from around March 2016. pkg correctly detected ABI =
"FreeBSD:11:amd64"; and installed the requested packages, but of course
I was missing all kinds of recent library versions (libssl, libpam,
fopencookie problems in mod_php, among others). This caused me quite a
headache at first, but then I went from my ancient current to 11-release
and now everything works like a charm. 

Searching online, I found only one reference to the situation I had been
in:

https://lists.freebsd.org/pipermail/freebsd-pkgbase/2016-June/000271.html.

Maybe pkg could print some kind of warning if you're behind too far on
current, though admittedly this is very likely some edge case and
updating to a release version fixed everything. 

pkg itself is really great, it's just so much faster and simpler than
portmaster or the old package system. Props to all the people who made
that possible!

Cheers,
Marc