Fixed keyboard handling, consolidated video handling.

Fixed keyboard handling, consolidated video handling.

The keyboard handler now properly emulates the //e's 2-key rollover.
However, we might have to add in a key repeat delay if it makes it so
that you can't type on the console anymore. This had to be done because
SDL will throw in key delay if you rely on it's SDL_KEYDOWN message and
this caused many games with keyboard input to be unplayable. Also, we
consolidated the video handling files, as there was very little in
video.cpp and so we moved it into applevideo.cpp and renamed that file
to video.cpp. Things are a lot cleaner as a result of this merge. :-)