Update todo.txt

todo.txt

@@ -1,14 +1,5 @@
 features:
 
-- Add macros that would allow to make some compile-time options (e.g.
-  resolution) global variabes instead and allow them to change at runtime.
-
-- presets that can be optionally selected and  will configure other constants
-  (e.g. a "low memory sort strategy" will turn z-buffer off and turn
-  back-to-front sorting on).
-
-- Add and test a doxyfile.
-
 - Helper functions for e.g. retrieving and caching UV coords etc. Maybe these
   should be in a separate file?                            DONE