* Python interpreter discovery
* No longer blindly default to only `/usr/bin/python`
* `ansible_python_interpreter` defaults to `auto_legacy`, which will discover the platform Python interpreter on some platforms (but still favor `/usr/bin/python` if present for backward compatibility). Use `auto` to always use the discovered interpreter, append `_silent` to either value to suppress warnings.
* includes new doc utility method `get_versioned_doclink` to generate a major.minor versioned doclink against docs.ansible.com (or some other config-overridden URL)
* docs revisions for python interpreter discovery
(cherry picked from commit 5b53c0012ab7212304c28fdd24cb33fd8ff755c2)
* verify output on some distros, cleanup