Sub-classing DBIx::DWIW

Commonly implemented methods

  package MyDBI;
  use     DBIx::DWIW;
  @ISA = 'DBIx::DWIW';
  use strict;

  sub LocalConfig($$) {
      ## called with config or DSN name, returns
      ## Connect() parameters
  }

  sub FindSlave($@) {
      ## called with config, returns new config
      ## probably with an updated Host field.
  }

  sub RetryWait($$) {
      ## called with the error string that triggered
      ## the decision to retry or wait
  }