=head2 Documented that when() treats specially most of the filetest operators
-=head2 Documented that DESTROY is subject to AUTOLOAD, and the related optimisations.
-
=head2 Documented when as a syntax modifier
=head2 Eliminated "Old Perl threads tutorial", which describes 5005 threads.
pod/perlthrtut.pod is the same material reworked for ithreads.
-=head2 Removed a link to the attrs pragma, which has now been removed.
-
-=head2 update PERL_MEM_LOG in perlhack.pod
-
=head2 Correct previous documentation: v-strings are not deprecated
With version objects, we need them to use MODULE VERSION syntax. This