More Interactivity.

Things that can be dragged should react to the mouse being there.  So I'm starting to put that in each of my puzzles.  

Right now the process is simple:

Create: mouse_in=false;

Mouse Enter: mouse_in=true;

Mouse Leave: mouse_in=false;

image_alpha=1-mouse_in/7;

This was users can discover the interactivity a little more obviously.  Hopefully.  The effect is subtle, like I like, but noticable enough to suggest that the tiles are, in fact, tiles.

I also need to work on my older buttons.  They don't have a mouse-in effect yet.  Same reasons.