v4.0.0 (new APIs)
expose TypeFactory for direct creation of non-tuple types;
use TupleType.decode impl for all ABITypes;
move TupleType.format code up to ABIType;
fix plus sign being allowed in front of fixed types and array lengths;
make ArrayType.DYNAMIC_LENGTH public;
SHA-256 (headlong-4.0.0.jar): 60901358a33d78cb9893e4d839113e757a6d31a6842da37d16254019c07873eb