De-cleverify Driver::Base.ACTION_METHODS constant.
Update a few more yardoc comments for formatting.
Add docs & specs for Driver::Base.no_parallel_for.
Complete yard docs for Kitchen::Driver::Base.
[Breaking] Remove 3 pass-through busser methods on Kitchen::Driver::Base.

The three methods are:

* `#busser_setup_cmd`
* `#busser_sync_cmd`
* `#busser_run_cmd`

The suggested alternative for Driver authors is to access the Busser
command strings via the `#busser` method:

* `busser.setup_cmd`
* `busser.sync_cmd`
* `busser.run_cmd`