* Replace FAMs with `std::vector`s (or one `std::string`) in four `struct`s
* Anonymous types declared in an anonymous union are also non-standard
Only Clang complains about this (-Wnested-anon-types)
* Fixes from temporarily re-enabling more compiler warnings
* More edits suggested by cppcheck
* Fix hanging on append_yylval_string
* Fix FOR loop increment