Comment 8 for bug 1878234

So to summary what I have in mind:

Let's add a global config option about how config annotation is handled:
   -. disabled (the default)
   -. whitelist: only config options that we have identified to be secure are allowed
   -. free-for-all: all config options are allowed to be altered via annotations, not for end users, upper layer should have proper validation on user's input

What do you think?