Better preview image capabilities

Added more output options about the generated preview image:

-psm :  preview image Minitel size: 640x480 pixels (default)
-pss :  preview image Small size: 1 pixel origin = 1 pixel on preview (like before)
-pdwNNNN :  preview image specific size: width NNNN. height will be NNNN*3/4. eg: -pdw1280

-pnf :  don't include top row default "F" cursor in the top right corner, in preview image
        (default is: add "F" cursor in the top right corner, if there is enough space)

-pnb :  don't draw border on preview image (default is: Preview with border)

Credit image "eye" : Andriyko Podilnyk unsplash.com/@yirage