Remove Haali DirectShow support.

It had become a burden rather than an asset, especially since
the Haali splitter itself is rarely - if ever - updated,
and [most?] users (should) have switched to LAV Filters already.

The Haali Matroska parser remains, because it's separate from
this mess.  Maybe it should be removed too, but this comes first.
Regenerate buildsystem after Haali removal.