changing install location

[George Georgalis <george%galis.org@localhost>]

Hi - I'd like to install a set of packages with tag 2011Q1 in
/usr/pkg-2011Q1 while I continue to use an older tag in /usr/pkg

I was thinking setting LOCALBASE would get me a long way
there, but I'm not sure how to deal with PKG_DBDIR (to use
/var/db/pkg-2011Q1)

If I just keep LOCALBASE and PKG_DBDIR set correctly when running
programs like pkg_chk will I be able to simultaneously maintain
each tag with their respective prefix? Or will there be other
problems?

-George