Mac OS X gui: Label the option "Check for VLC update automatically" rather than "Check for update when VLC is launched".

Mac OS X gui: Ask the user if she wants to check update on startup. And if so, check for update only every two days.

Allow changing the subpicture filter chain at runtime. (This currently kind of segfaults some of the time (after 2 changes) ... somemore bughunting is needed)

Add calls to config_Put* to make sure that the configuration values survive a filter instance destruction.

Don't use stupid dirac patch.