MO test basic-010 should be simpler about epub-testsuite

[OriIdan]

I haven't seen any RS system that does not have controls in case of MO but I agree that this wording would be simpler.

[marisademeglio]

There is one RS that I got a report about which does not have MO controls. The evaluator was not sure how to answer this test (in its current form).

[pettarin]

I agree. I propose what follows:

Current:

If there is a play/pause button that starts playing audio narration for the text on this page, then the Reading System supports Media Overlays (MO).

Proposed:

If audio rendition is started automatically after this page has been rendered, or if there is a play/pause button that starts playing audio narration for the text on this page, then the Reading System supports Media Overlays (MO).

Rationale: I was not able to locate the point of the EPUB 3 MO specification where a "play/pause button" (or other visual control) is required/recommended, albeit that is a common choice. If I am wrong on this one, please disregard this issue (and maybe reference the point in the specs that I have overlooked, thank you.)