New release of hashable

I've just made a new release of the hashable package. New in this version is the possibility to provide a custom salt when hashing a value. This is useful if you need to compute several different hash values for the same input, for example when implementing cuckoo hashing.

There are also a few improvements and bug fixes in this release. Most notable is the increased resilience to badly distributed hashes due to leading zeroes in input strings or tuples.

Thanks to Jan-Willem Maessen and Antoine Latter, who both contributed to this release.