Use parse_docstring in required_module_list (fixes #3727)
Use parse_docstring in required_module_list (fixes #3727)

Should now work for the previous 'Required python modules: ' method, and
the RST ':depends:' method.

Does not parse ':optdepends:' as of yet, as that's not currently needed

saltstack/salt,saltstack/salt,saltstack/salt,saltstack/salt,saltstack/salt