Install ExtUtils::MakeMaker with CPANM

This updates ExtUtils::MakeMaker to the latest version.

Fixes https://github.com/travis-ci/travis-ci/issues/2740
Add Perl runtime that has -Duseithreads

This will coexist with -Duseshrplib, and will be named -extras.

For backward compatibility, `5.*-shrplib` aliases are also created.

This fixes https://github.com/travis-ci/travis-ci/issues/2709
Update changelog
Merge branch 'ha-feature-perl-extra'