libvlc: Properly raise an exception if something goes wrong in libvlc_media_get_duration and libvlc_media_is_preparsed.

Note: We should probably throw exception, and handle them a bit more gracefully, as we do in vlc_app.

buidsystem: Fix package-macosx target so that they build VLC-release.app first. And make sure -zip contains Read Me.rtf.

possible.

avcodec: use cast to avoid warning about this const. It's a rare case where we use a dummy empty palette that won't change and we don't want to recreate it every time either.

is too far away (> 500ms) from a key frame.
It will reduce seek precision but the implementation of
ES_OUT_SET_NEXT_DISPLAY_TIME is not good enough yet.

Signed-off-by: Rémi Denis-Courmont <rdenis@simphalempin.com>