Add option in Makefile to compile for large/fullscreen terminal windows

Created by: everlastingwonder

I personally like to have my terminal window set to fullscreen; unfortunately, my monitor is wide enough that the fullscreen terminal is more than 255 characters wide (which ncurses apparently doesn't like). This meant that when I first compiled frotz and ran a game, the entire thing was squashed into a column about 10 characters wide on the left-hand side of the screen. These commits add an option to compile frotz such that if it is invoked with a width greater than 255, it will simply set the width to 255, rather than giving ncurses a bad value; this was the workaround I used, and I thought other people might benefit from it as well.