Add "rescreen" program

From:
https://raw.github.com/sciurus/splatbang/adabb7b7724fce4d0d83e694944a4b9faca37096/rescreen

Also see:
http://www.polibyte.com/blog/automatically_fixing_the_gnu_screen_environment
bashrc: Add directive needed by rescreen

Just doing what the program told me to do. :)