complexity attacks and also because we discovered that it exposes hash
ordering dependency bugs and make them easier to track down.
+=head2 PERL_HASH_SEED enviornment variable now takes a hex value
+
+PERL_HASH_SEED no longer accepts an integer as a parameter, instead the
+value is expected to be a binary string encoded in hex. This is to make
+the infrastructure support hash seeds of arbitrary lengths which might
+exceed that of an integer. (SipHash uses a 16 byte seed).
+
+=head2 Hash::Util::hash_seed() now returns a string
+
+Hash::Util::hash_seed() now returns a string instead of an integer. This
+is to make the infrastructure support hash seeds of arbitrary lengths
+which might exceed that of an integer. (SipHash uses a 16 byte seed).
+
+=head2 Output of PERL_HASH_SEED_DEBUG has been changed
+
+The environment variable PERL_HASH_SEED_DEBUG now shows both the hash
+function perl was built with AND the seed, in hex in use for that process.
+Code parsing this output, should it exist, must change to accomodate the
+new format. Example of the new format:
+
+ $ PERL_HASH_SEED_DEBUG=1 ./perl -e1
+ HASH_FUNCTION = MURMUR3 HASH_SEED = 0x1476bb9f
+
=head1 Deprecations
XXX Any deprecated features, syntax, modules etc. should be listed here. In