Re-worked the YARD transformer and handlers to attach parameters to the
resulting code objects. Some architectural debt was incurred in the interests
of producing a working prototype quickly.
Use `require_relative` for all components under Puppetx. This makes it possible
to load `pupetx/yardoc/yard/plugin` outside of Puppet as a YARD plugin.
Also fix the `yardoc` face so that Puppetx bits are loaded _after_ feature
checks.
The `YARDStatement` class is an adaptor that composes a `Pops::Model` instance
along with applicable `Pops::Adapter` and presents a familiar interface for
`YARD::Handler` objects to work with.
Charlie Sharpsteen