--console-title doesn't work in tmux (or GNU screen)

[zgracem]

I do most of my terminal work inside tmux, so I almost never get to take advantage of the delightful --console-title option. Would it be possible to detect when youtube-dl is running inside tmux (or GNU screen, I suppose) and add the appropriate DCS to the escape sequences?

• For tmux: \ePtmux;\e\e]2;${window_title}\a\e\\
• For screen: \eP\e]2;${window_title}\a\e\\