Close To Final Version

With the release date getting closer this update concentrates on fixing the little things. 

• cross hair is a bit wider and bigger
• cross hair scales with fov, so that it doesn't change size when changing fov
• uploaded a solution video for level "Faster, Higher"
• some parameter fiddling to fix visual glitches in "Faster, Higher"
• change to leve "Hold On" to avoid unintended solution
• fixed a possible one-frame-flicker when changing status of frame
• changed material for objects that can't go through frame to increase distinguishability from objects that can enter frames
• improved memory usage and performance of rendering of shadow texture
• hint machine, spheres, character, fences, next level button and level exit cast shadows, now
• so far the light direction changed when looking through a frame in such a way that the light direction stayed the same relative to the direction of the camera. This had the weird effect, that in some cases objects cast a shadow on one side, but are completely in the shadow when looking through a frame. So now the light direction always stays the same when shadows are enabled (for disabled shadows the old behavior is kept). 

With these fixes I consider Frame to be close to its final version. Only the shadows are still glitchy and will require some work.