Add some missing perldoc pages from 5.22.0

[tm604]

There's some pages in perl5.22.0 that aren't listed in Perldoc::Section. I suspect this will be an incomplete list: my quick hack to generate this list used:

perl -Ilib -E'use Perldoc::Section; my %seen = map {; $_ => 1 } map @{$_->{pages}}, @Perldoc::Section::section_data; say for keys %seen' | sort 

then compared against

for i in $(find ~/perl5/perlbrew/perls/perl-5.22.0/lib/5.22.0/ -name "perl*.pod"); do basename $i; done | sort > modules.lst

using comm(1):

comm -13 sections.lst modules.lst > missing.lst

this is probably something that could be automated, although there's a few false positives (perl_delta, perltw/perljp, perlfaq_).

A second issue that this doesn't resolve: the perldoc.perl.org pages do not have some of the core modules, such as IO::Socket::IP. This would require using the correct Perl version when running the build_.pl scripts, I suspect pre-5.18 was used. Since modules can be added or removed, I think each build-_.pl run needs to use a perlbrew (or equivalent) clean install for the relevant version, rather than trying to run them all from a single perl install?