- allow treatment as one-character string constants as character constants. This became necessary because name constants already use single quotes and are much harder to repurpose due to a higher degree of ambiguity.
- fixed: protected methods in structs were not usable.
Note that this completely disables the newly added keywords 'play' and 'ui' for unversioned code to allow using them as identifiers as I have found at least one mod that uses a variable named 'play' that would have been rendered broken otherwise.
This also disables many ZScript only keywords for other parsing jobs.
