Compatibility with the caca and x11 vouts needs to be checked

Since we require libmpeg > 0.3.2 there is no need for this check.

directory: accepts any existing directory and will use the filename component of the update URL (old behaviour). This option no longer requires you to provide a string that ends with the pathsep.

filename: write directly to this filename. Existing files will be overwritten.

NULL: will write to filename component of the update URL. likely in the CWD.

Win32 Vout: after the previous fix of Win32 Vout, the fullscreen mode wasn't kept for the next item. This fixes that.

It closes at least #2119 (on any vertical scaled only subtitle).

Can pl_Hold return NULL ?

p_sys cannot be null here.