If they can be passed through the MRL, there is no extra exposure in
passing them as options.

The cookie is not secure. Depending on the master input (or other
slave inputs), it might be possible for a third party to inject bad
cookies. The caller shall implement appropriate sanity checks.

This introduced way too many bugs.
Close #3297 and "activate-subs hide the video" bug and a few more.
This is way suboptimal, but no fix works in a reliable fashion so far.

Volatile/unsaveable options are now always internal implicitly.

Signed-off-by: Rémi Denis-Courmont <remi@remlab.net>

Signed-off-by: Rémi Denis-Courmont <remi@remlab.net>

Signed-off-by: Rémi Denis-Courmont <remi@remlab.net>

This can reportedly be used to overlay HTML content on top of the VLC
widget. That being said, overlay is not a portable option *ahem*.

This is too late to change command line options anyway.

We will print a fatal error afterward anyway.

Yes, I know, I am not using 1.4.1...

Most probably nobody uses this (in VLC context). In fact, it would
cause many existing VLC command line examples /out there/ to fail
mysteriously.

This simplifies the code a little bit and kills a static variable.