What's the best way to modify the built-in classes? I want to
have full control over the code, so sub-classing won't work.
Maybe the best way is to copy the source into my project
directory, i.e. Button.as if I want to change the default Button?
But I ran into a problem: Flex Builder cannot find Version.as. I
tried adding framework/src/mx/controls (the folder than originally
contains Button.as) to the additional source folders (Properties
> flex build path) but it still can't find it...