Wibbly wobbly world

Hooray! I've implemented a lot of new effects. Here is a list.

Cookie-cutter fades and wipes: I implemented a whole lot of these and removed the pixel-type fades. I like them better and I'm just putting together a good working set of them. Unfortunately I'm going to have to go through every level and change the fade types used because they don't correspond well to the old types.

Wavy screen effect: When you get enough mushrooms the screen goes all wavy. Like "Touch fuzzy, get dizzy" in Yoshi's island, except not quite as good. I needed to stick to simple line shifts because otherwise it would take too long to process each frame.

Hit masking: When you shoot an enemy, they flash orange like in the Metal Slug games.

I still want to implement a new sky rendering system to make great parallax very easily. It would do this by calculating the scan position of the parallax (like raytracing, I guess) and then plotting it. The speedup would be by combining it with the background rendering so it only rendered the parallax in the 'holes' in the background.

I might also make an underwater effect or similar.