Cosmetics and documentation for the hooks.
Only report error for important hooks and try to run anyway.

Mostly DVD playback is impacted if some hook fails but the user might not plan to play DVD and it might work anyway.
Make the non-system audio renderer names translatable.

Ticket #3725.
Cosmetic: Don't use spaces between slashes in internal filter names.

Ticket #3725.
Use conversion constructors to work-around confusing AStyle styling.
Use a bitcheck instead of casting (WIP).

Fixes CID #965944.