1.351     2007-03-22
          packaging improvements

1.35      2006-07-11
          Fixed version required for Sys::Hostname (thanks BARBIE)
          plan tests (for compat with older harnesses)
          keep a unique per pid part to fend of encroaching collisions (rjbs)
          remove ineffective caching mechanism (rjbs)

1.31      2004-12-22
          Stopped using Time::HiRes. Instead, generate a pseudo-random string.
          Cache user portions of the address to ensure uniqueness.
          Add purge_users() method, undocumented currently. Experimental.

1.2       2004-09-27
          INCOMPATIBLE: Removed trigger code, just subclass to override
          behaviour.