2.2.0
Add tests/IdnaTest.*
Add test-glibc, based on API traces from the glibc AI_IDN tests
gen-utc-test.pl: skip lines which would have generated empty tests
valgrind: use suppressions file by default
Add test for round-trip failure
Fix C++ build errors
Fix label length check for idn2_register_u8()
Add compiler-suggested function attributes
Stricter check of punycode-decode input