Log Message:
Version 1.44 - 24th Janurary 2008
    + Fixed some small typos in the POD.
    + Added "on_missing_ds" parameter to the new()
      constructor method to detemine what action should
      be taken when the user tries to update or insert
      new data point values in an RRD for a data source
      name that does not exist.
    + Added "tmpdir" parameter to the new() constructor
      method to force any temporary files to be created
      in the specified directory.
    + Added a number of additional TRACE() statements
      in the code to aid debugging with the DEBUG=1
      environment variable.
    + Changed graph() so that there is no longer an
      AVERAGE VDEF vname generated for each data source
      by default.
    + Changed graph() method to allow undef or ''
      (empty) values to be passed in for the sources
      parameter.
    + Added a new example to RRD::Simple::Examples
      to show how to generate predictive graphs to
      provide basic capacity planning.
    + Added a new "periods" parameter to the graph()
      method to restrict which graphs will be
      generated.
    + Updated version of rrd.me.uk in the examples
      sub-directory of this distribution, inside the
      "rrd-server" directory.