v8.0.0 (API refresh)

redesign RLPEncoder API;
ByteType no longer extends UnitType;
reject Records with out-of-order keys on decode;
reject unexpected RLP lists found in Record items;
improve Record encoding performance;
make RLPItem Comparable;
make Strings.URL_SAFE_FLAGS private;
limit Function names to 2048 chars;
limit ABI types to 2000 chars;
abort array ABI decode early if input obviously too short;
raise max decodeable array length to 2^19 - 1;
rename JsonUtils.parse to parseElement;
remove JsonUtils.getArray(JsonObject,String,JsonArray);
remove JsonUtils.toPrettyPrint;
for better security, do cryptographic hash comparisons in constant time;
fix misleading error message;

SHA-256 (headlong-8.0.0.jar): ce55ec4b3a9c9087f9f9cfad304e79688e7421e75b1b056853ecf5a79611f754

Full Changelog: v7.0.0...v8.0.0