[tv] Remove since it is not maintained and does not work.

It has been a long while since I used tv, and as the page it took
content from changed it format, it stopped working.  Because I have
no interest in fixing this, this commit removes it from repository.
[settitle] Use tput if available.

Instead of hard-coding the control sequences for setting the title
(or status line as the capabilities are called), use tput to send
them and to determine whether terminal even supports setting of
the title.

While changing settitle, also replace non-standard “echo -ne”
with printf, and change static “rxvt” (if called with no
arguments) to “$TERM”.