Support reading stream duration and seeking for MPEG-PS streams.

[botaydotcom]

Split from issue: #4406.

[botaydotcom]

This is done now.

[cncb-gh]

Can this be extended to MPEG-TS or is it too different? Thanks.

[ojw28]

It's already extended to TS.

[cncb-gh]

So, the newest build now supports seeking in TS? Great!

[ojw28]

The latest dev-v2 branch does. This functionality will be in the 2.9.0 release.

[cncb-gh]

Excellent. Is there a release timeline posted somewhere? Many thanks to you, @botaydotcom, @andrewlewis, and anyone else working on this fantastic project!