Made rotating a little faster by not pushing cx.

Fixed problem where first character is always ignored.
Fixed the character map to not interfere.

Also have something different for shift + up or down arrow as opposed to
just pressing up or down. (Will mean up page versus up row).
Simplified the logic for inputting a character and printing a string.

Added code to scroll up a line or scroll down a line and did error checking.
Took the make cursor visible procedure from VideoInt to JdosInt because it
is only called there.