Only files containing classes or interfaces should be added to the dynamic-loading code registry

Currently Views Highcharts adds files to the dynamic-loading code registry that do not have classes or interfaces. The only file that contains a class is the views_highcharts_plugin_style_highcharts.inc file, so it should be the only file added to the "files" key in the .info file. Refer to http://drupal.org/node/542202#files for more information.