+2009-12-01
+ * added reading native Sokoban levels and level packages (XSB files)
+
+2009-11-25
+ * fixed bugs in (auto)scrolling behaviour when passing ports or when
+ wrapping around the playfield through "holes" in the playfield border
+
+2009-11-24
+ * changed internal playfield bitmap handling from playfield sized bitmap
+ to screen sized bitmap (visible scrolling area), therefore speeding up
+ graphics operations (by eliminating bitmap updates in invisible areas)
+ and removing playfield size limitations due to increasing bitmap size
+ for larger playfield sizes (while the new implementation always uses
+ a fixed playfield bitmap size for arbitrary internal playfield sizes)
+