Complete addch

echo-char and new-line now take window arguments instead of ncurses
window pointers.
Added alert (beep and flash)
Cleaning up exported symbols

* Removed a lot of obsolete symbols from package.lisp
* Removed obsolete comments from kernel.lisp
* Refactored refresh.lisp
Renamed .background-char to .background for brevity
Added an alternative character set (ACS) example
Example for beep/flash alerts
Split of the initialize-instance aux method.
Basic init test added, cosmetic updates to others.