is_media_preset -> is_media_present in BlockIOMedia

[ColinFinck]

This is a breaking typo fix. But as main already contains some breaking changes since 0.16, I feel that it's the right time to fix it.

[nicholasbishop]

lgtm, will run the CI once #494 is resolved

[phip1611]

btw, I just learned recently, that in Rust's definition of semantic versioning for 0.x.y versions, each bump of x should be treated as breaking change.

Apart from that, I think breaking changes in nightly software that has a 0 as major version number are most of the time perfectly fine if the code change itself is sensible. Our users are no beginners anyway, so they should be able to easily cope with that. Our changelog is a good guideline.