Proper translation of prefIntroCaptions

…tion

Update Dutch translation

Also eslint fixes

Also eslint fixes

Also use "e" instead of "_" for ignored caught errors

Caught with eslint. At least, they look like bugs. Hopefully the buggy
behavior wasn't important.

Also eslint

This keeps with our allowing unused principle, and also fits better,
Vimeo does document these as "events"

Looks like various elements used to get passed around differently, but
the old references are still present, just unused or always undefined.
Get rid of 'em.

Also eslint

More accurate link name.

Fixes #731

Fixes #735

7 additional unused strings.

See #715

The large input validation test is obsolete, as Able Player rejects input greater than 1000 characters as of 4.8.0.

- Reduce the size of largeInput
- Catch the thrown Error and test response.
- Adds increased timeout on validate test run.

Avoids duplicate logic.

This is only ever used horizontally, so lets simplify a bit.

These are always set to specific static values.

Fixes #675