marquee filter. Also change logo parameter transparency to
opacity for consistency with marquee.

Signed-off-by: Rafaël Carré <rafael.carre@gmail.com>

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

So far, the input was attached after it inherited quite a bunch of
variables. This did not quite work. The problem lies in the dual use
of object attachment: variables inheritance and tree search.

Nowadays, the input object should not be looked for before it is
initialized. Only children objects use vlc_object_find anymore, and
they can only exist while the input is fully initialized. Other code
paths use playlist_CurrentInput() or such, which only ever return an
already initialized input (from input.c:Create()).

(N.B.: I wonder if there aren't similar issues in VOUT and AOUT)

This is not needed, and not a good idea.

Fixes: Qt playlist was not able to display the SAP service discovery
because Qt relies on a call to playlist_ChildSearchName().
The name defined as module longtext must be the same as the SD probe
name.

Use var_Inherit* on parent object in playlist_Create()
Check "media-library" before calling playlist_ML*()

When the first entry is read and has a clientskip attribute, It keeps a
backup of the playlist entry for later use. If another entry exists
without clientskip attribute, the backup will be discarded.

When finished parsing, we search for a backup, if found, we add it (it
means we did not find any entry).

Replace arbitrary sleep delays by active waiting of state change
Add state change wait where needed (after play()/next()/previous())

This reverts commit f2564c11.

...instead of the configuration. As a side effect, the command line
parameter should not be visible in the preferences, and more importantly
not be saved as part of the persistent configuration (fixes #1428)
(and really fixes older #1106).

We might be able to remove a few "dummy" change_unsaveable(). Some of
them really were just work-arounds for this bug. In principle, we could
possibly remove all of them as long as we keep add_internal().

Note that this commit will render any command line option inoperant if
it is read with config_Get*() instead of var_Inherit*() or var_*Get*().
I already fixed the most commonly used occurences, but there are some
left, especially inside plugins.