It appears that ExtUtils::MakeMaker versions older than 6.11 do not
implement the DESTDIR mechanism. So add a test to the generated perl.mak
to detect when DESTDIR is used along with a too old ExtUtils::MakeMaker and
abort with a message suggesting the use of NO_PERL_MAKEMAKER.
Signed-off-by: Brandon Casey <casey@nrlssc.navy.mil> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>