cli: Close the file descriptor as well as deleting the pipe file.

This avoids a ResourceWarning, and explicitly signals the end of the stream
to the player, which will avoid a deadlock if we want to wait for it to exit.
cli: New option to wait for the player process to exit.

This avoids an awkward behaviour with M Player and MPV, which do not work
well in some cases when running as a background process.

The “--player-no-close” option lets the player continue to run while
Livestreamer exits. This means that control returns to the shell, while the
player runs in a background process. I noticed that if the standard input of
M Player or MPV was _not_ used to stream the media (e.g. the “--player-http”
mode was used instead), then the player would change the terminal settings
after Livestreamer exited. This would interfere with Bash and Readline.