This lists only the changes for the current release (v1.23) over the last
version, since CHANGES is now quite big:

* Math::String::Charset used Math::String::Charset::Wordlist, instead of
  requiring it. This means install of Math::String failed w/o an installed
  Math::String::Charset::Wordlist, which in turn needed installed Math::String.
  Oups.
* removed the needless shebang (#!/usr/bin/perl ..) lines
* added "lib => 'GMP'" to all 'use Math::BigInt;' lines
* prerequisite Math::BigInt v1.65
* 595 tests
