Check for unused config flags and remove previously_normalised

[giltho]

In the past, JaVerT used to allow to normalise assertions and save that state somewhere, to save some time.
However, this feature is not used anymore, and the code to do that is half dead.
For example the normalised flag Spec.t, BiSpec.t and Pred.t can be removed, and any code that depends on them (including parser and lexer).

It would be good to check other config flags to see if they're still used or not. If you're doing this @NatKarmios and there are unused config flag, ask me about them before removing them :)