_requested_version of bundle is now adequately captured by [Prereqs::AuthorDeps]
require_module is better if an exact version is not required
simplify these greps
test that %extra_args is used for installer plugins
switch some uses of List::MoreUtils to List::Util
apply %extra_args to installer plugins in a more generic way
Dist::Zilla::Plugin::* modules automatically declare the minimum version needed for sane metadata production
shorter expressions
active airplane mode with DZIL_AIRPLANE=1
give slightly more meaningful names (for diagnostic output) to these plugins
convert main module pod to README.pod for committing to the repo, rather than README.md (it was ingy's idea!)
remove the old README.md at release time when replacing with README.pod
new [Test::ReportPrereqs] generates an extra file
whitespace
die if *.xs exists in repository but Makefile.PL does not

This is not easily testable because the pluginbundle config is fetched before
Dist::Zilla::Tester changes into the source directory - so the file layout
during tests is different than during a real live distribution build.
Dist-Zilla-PluginBundle-Author-ETHER-0.066

          - internally-hardcoded extra arguments to be passed to optional
            plugins are now handled in a more generic way, now encompassing
            all plugins that might be used
          - minted Dist::Zilla plugins now contain an extra bit of needed
            prereq declaration, for valid metadata production
          - airplane mode can now also be enabled via the DZIL_AIRPLANE
            environment variable
          - now converting the main module to README.pod (pod instead of
            markdown) for committing to the repository
          - fix test of expected files produced by bundle to handle the new
            data file put out by [Test::ReportPrereqs] 0.014.
          - XS-based distributions (*.xs files found in repository root) must
            now have a basic Makefile.PL provided to assist development