more zoom/center fixes. RLEs now load centered and visible.

TODO.md

@@ -2,9 +2,16 @@
 
 - changing options mid-game has no effect in most cases, even after a restart
 
-- RLE file loading works, but if world is larger than screen, center is invisible.
-
 - Statefile loading does not work correclty anymore. With larger grids
   everything  is empty.  With square  grids part  of the  grid is  cut
   off. Smaller grids load though
   
+- Also  when loading a state  file, centering doesn't work  anymore, I
+  think the geom calculation is overthrown by the parser func. So, put
+  this calc into its own func and  always call. Or - as stated below -
+  put it onto camera.go and call from Init().
+  
+- Zoom 0 on reset only  works when world<screen.  otherwise zoom would
+  be negative So, on Init() memoize  centered camera position or add a
+  Center() function  to camera.go.  Then on  reset calculate  the zoom
+  level so that the world fits into the screen.