Strip quotes around commands.
  Avoid template-expansion of variables.

  This now happens in the driver in Templer.  This has to be done
 so that we can expand both variables in the page and in the global
 configuration file.
  Perform variable expansion.

  This happens here so that we can do it in both *pages* and in the
 global configuration file.
  Updated test-cases.

  Now that we expand the variables outside the Templer::Site::Page
 object we must do this manually in our test suite.
  Perltidy
  Don't strip quotes.  D'oh.
  Added example of running shell command.

  In new sites this will insert the date in the footer of new pages.