Also add support for the Private Use Area characters and check for
valid ISO 8859 character sets.

Most progressbars are modal tasks.
Interruptible progress dialogs should be modal then.

Frontend features are in an enum, so ifdef does not work.

programs

We assume C99 nowadays.

The decoder pictures needs to be read back for rendering subtiles/OSD so
it's better to always use fast pictures for the decoders.

But as we don't have any module that provides slow pictures and are still
usable for DR...

When direct rendering was enabled, we used the display pool which can be
empty, leading to pictures being skipped.

Signed-off-by: Konstantin Pavlov <thresh@videolan.org>

It doesn't compile though, and is using a broken interface like crop

It is known to crash due to invalid buffer handling. On Linux, I get
memory accesses before the start of the audio buffer. It also crashes
on Windows. Until someone cares to fix it, and I think it really never
worked correctly, lets use the "ugly" resampler, which is not too ugly.

This should fix #3631, #4366, #4491 and possibly others.

Broken since d14e0b78