yt-music.sh: Handle m4a.

Signed-off-by: Rüdiger Sonderfeld <ruediger@c-plusplus.de>
yt-music.sh: Handle new youtube-dl version.

Signed-off-by: Rüdiger Sonderfeld <ruediger@c-plusplus.de>
latex: sortcites

Signed-off-by: Rüdiger Sonderfeld <ruediger@c-plusplus.de>
gcc: suggest

Signed-off-by: Rüdiger Sonderfeld <ruediger@c-plusplus.de>