Add default terminfo for screen-256color. Extracted using infocmp.

Signed-off-by: Rodrigo Belem <rodrigo.belem@gmail.com>
Fix `less' displying italics instead of reverse

Fix found at tmux FAQ:
http://tmux.svn.sourceforge.net/viewvc/tmux/trunk/FAQ
For future reference:
http://pubs.opengroup.org/onlinepubs/7990989799/xcurses/terminfo.html

Signed-off-by: Rodrigo Belem <rodrigo.belem@gmail.com>