fix(REST): issue2551383; improve errors for bad json, fix PUT docs While adding fuzz testing for email addresses via REST /rest/data/user/1/address, I had an error when setting the address to the same value it currently had. Traced this to a bug in userauditor.py. Fixed the bug. Documented in upgrading.txt. While trying to track down issue, I realized invalid json was being accepted without error. So I fixed the code that parses the json and have it return an error. Also modified some tests that broke (used invalid json, or passed body (e.g. DELETE) but shouldn't have. Add tests for bad json to verify new code. Fixed test that wasn't initializing the body_file in each loop, so the test wasn't actually supplying a body. Also realised PUT documentation was not correct. Output format isn't quite like GET. Fuss tests for email address also added.