rtorrent status in terminal window's title

[drzraf]

It's very handy for the terminal window's title to show the name of the application currently running.
It may allow to adapt some desktop elements.
But it's even more useful if it show significant information.

Mutt provides such feature via the xterm_set_titles option implemented by simply sending the Xterm (defacto standard) escape sequence to stderr (\033]0;FOO\033]0;):

• https://github.com/muttmua/mutt/blob/1a9fea6f9aa506cd2ac8222cee05889b775f8613/curs_main.c#L133
• https://github.com/muttmua/mutt/blob/1a9fea6f9aa506cd2ac8222cee05889b775f8613/curs_main.c#L192

That could be a handful improvement.