The show, hide and moveTo routines inherited from Widget only make sense
if you have a reference to the outputElement, which may not actally be the
real one (e.g. in the case of samsung_maple), and may require special
handling on any given device depending on how the video on those items works.

Passing these through to the media controller allows them to be deal with on
a per-device basis without breaking away from the Widget API.