This makes it more maintainable, as it means that POD can be syntax
highlighted, and it makes it obvious whether the documentation needs to
be updated or added if missing.
The usual reason for placing POD at __END__ is for performance reasons,
but the very slight parsing cost does not compensate the burden of
having it there.
Change-Id: I5e0d9e59a5331d5c54a9502176f8009da6b70946