Do not install to INSTALLDIRS after 5.11 RT#89756

This can cause problems with dependency installations.
See ticket for more details.
Do not try to drop privs if given -U RT#87837
Cleanup code related to mandoc(1). RT#85844

Thanks to Ingo Schwarze <schwarze@openbsd.org> for the patch.

    * No need to parse mandoc versions, just ask the program itself
      whether it can handle -Tlocale.
    * Remove some dubious advice.  Mandoc is only preferred on
    * OpenBSD, and in that environment, i don't think using the
      groff from ports is better for formatting pod2man(1)-generated
      manuals than using the mandoc(1) from the base system.
    * No need to pass -mandoc to mandoc(1), it's the default and
      will ever be.
    * No harm done passing -man to mandoc(1), it just works.
Match =item much more carefully RT#86795

Count list entries and exits even outside of the
context of a found block of code.  Previous code
was leading to matches on things like 'size'
and 'precision' which are part of the sprintf
function and may confuse users because they're
not valid perl functions.
Bump to 3.22_01
Add a new exemplar to the corpus
Ignore some new stuff