Todo
----
+H: high priority
L: low priority
+[H] The scrollstart position still isn't the same as before the changes.
+[H] Frame ratio code has been changed and so the animation may need tuning.
+ Somebody do some testing and change the definitions regarding this.
+[M] When aborting a level, lives and score should remain the same as they
+ were before. Solution: make more dependency between the game engine and worldmap
+ or just backup those variables before starting a level.
+[L] Backscroll is really messed up right now :)
[L] change lispreader to throw exceptions instead of simply assert() on
syntax error
[L] tux sometimes makes short jumps in the endsequence, mostly when
[L] in the "Welcome to Antarctica" level, the blocks next to the first growup
look like there are 2 blocks above each other when bumping against them as
small tux...
+[L] Life counter should be decreased once the die-animation starts,
+ not when it ends
+[L] Enemies should turn upside down after being hit by an kicked
+ iceblock
- leveleditor crashs when pressing the button with the levelsettings