This commit works by vendoring the couple functions we still use from
puppetlabs stdlib (join and range), but removing the rest of the
puppetlabs codebase, and of course cleaning up our linter rules in the
process.
Fixes#7423.
Apparently, `puppet-lint` on Ubuntu trusty throws warnings for certain
quoting patterns that are OK in modern `puppet-lint`. I believe the
old Zulip code was actually correct (i.e. the old `puppet-lint`
implementation was the problem), but it seems worth changing anyway to
suppress the warnings.
We also exclude more of puppet-apt from linting, since it's
third-party code.
We start to use puppet-lint to lint puppet modules by default by
adding it to tools/lint (which controls our linter tool chain).
We also define a few puppet-lint rules to exclude.
Fixes: #9185.