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

It seems to take about 10s to scroll 100 items in my pc, and any longer than
that is just way too slow.

Based on an initial patch by Rafaël Carré.

 It closes #4278, partially closes #3152, closes last part of #3090.
 It does not fix audio losses due to potentially buffered data by
packetizers/decoders.

Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

- use libvlc verbosity
- reset default color after having displayed the messages

This code is unfinished, and is commited as a Proof-of-Concept
If people agree on it, we will go on this experiment, else revert.
A lot of the code is broken, you are warned.
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

flat/tree view seems to be controlled by playlist-tree option these days

- remove some messages logging dead code
- don't store the ncurses WINDOW, use global stdscr instead
- add some fancy unicode characters to the help
- factorize list navigation key handling
    all boxes now use the same code than PLAYLIST/BROWSE
    this means there is now a selector in every box
- break Redraw() in several functions
- remove fancy characters from Status box drawing code
    use the same layout than meta-info / info boxes
- fix a display bug in objects box
- simplify some functions and remove unneeded arguments
- avoid a strdup() in ReadDir() loop

        Known regressions:
- when switching back to PLAYLIST box, the selector will be set to the
  playing item only after the 2nd refresh (i.e. maximum 1 second later)

And improve consistency

Yes, this still works fine as long as it's used in that one place in
the VLM.