Remove empty tuple literal syntax.
Convert TupleFieldAccess into more generic FieldAccess
`exprlist` must be non-empty. Consuming syntax must handle empty case if needed.

Function calls no longer assumed to start with an identifier
Parse type parameter lists in function definitions
parse.html automatically opens after being built
make parse.png target actually work

but really it’s still useless, because it takes an hour to run
add test for parsing functions with type parameter lists