Bug#742477: mention how to correct a current xterm's title

[積丹尼 Dan Jacobson <jidanni@jidanni.org>]

Package: xterm
Version: 303-1
Severity: wishlist
File: /usr/share/man/man1/xterm.1.gz

Mention that to correct the current running xterm's title,
one must use
$ echo -ne "\033]0;NEW TITLE\007"