Unicode identifers

[blamario]

This PR, among other things, is a generalized replacement for the abandoned Lambda the Ultimate Reserved Keyword PR.

Rendered Proposal

[applePrincess]

Hi I am pretty much positive about this. But this syntax allows us to declare a type like ˻typeName or a function like ˹FunctionName This is confusing.

And I think this is caused by having one idCharacter class, so instead of using idCharacter for both conId and varId, declare two more idCharacter related classes idCharacterLarge and idCharacterSmall which is idCharacter \ small and idCharacter \ large, respectively. This could be one solution to this problem.