Move from surfaces to the SDL render system

Ever since VVVVVV was initially ported to C++ in 2.0, it has used surfaces from SDL. The downside is, that's all software rendering. This commit moves most things off of surfaces, and all into GPU, by using textures and SDL_Renderer.

Pixel-perfect collision has been kept by keeping a copy of sprites as surfaces. There's plans for pixel-perfect collision to use masks instead of reading pixel data directly, but that's out of scope for this commit.

- `graphics.reloadresources()` is now called later in `main`, because textures cannot be created without a renderer.

- This commit also removes a bunch of surface functions which are no longer needed.

- This also recaches target textures in certain places for d3d9.

- graphics.images was converted to a fixed-size array.

- fillbox and fillboxabs use SDL_RenderDrawRect instead of drawing an outline using four filled rectangles

- Update my name in the credits

desktop_version/src/Input.cpp

@@ -3072,9 +3072,6 @@ static void mapmenuactionpress(const bool version2_2)
     case 11:
         //quit to menu
 
-        //Kill contents of offset render buffer, since we do that for some reason.
-        //This fixes an apparent frame flicker.
-        ClearSurface(graphics.menuoffbuffer);
         graphics.fademode = FADE_START_FADEOUT;
         music.fadeout();
         map.nexttowercolour();