Fix up ncurses interface so that it handles resizes correctly.

Fix up ncurses interface so that it handles resizes correctly.

Removed the readline library (still available using if HAVE_READLINE is defined)
since it really doesn't play well with ncurses.  The only real feature it added
was command completion, and it didn't really handle it completely correctly anyway.
(If readline printed a completion list, it completely screwed up the screen.)

We now use the wgetch ncurses interface to get input; this allows the PGDN and PGUP
keys to work correctly, and also helped fix up the resizing logic.