Add an option to remove comments but keep ones that contain timestamps

[lawrencehook]

For example, videos that are a music album will often have a comment with timestamps pointing to the beginning of each song. Would be nice to only show that comment when comments are otherwise hidden.

[lawrencehook]

This is tricky. Requires a unique approach to hiding elements. Don't think it can be css only, like the rest

[lawrencehook]

Implemented as of 4.3.10

[lawrencehook]