Use module_load_include() instead of require/include to avoid registry problems for the media module

Here is a patch that does this.

Here's another version with more calls changed from require_once to module_load_include.

Good point. I am assuming we are loading external files because we don't want the media.module to be get too big. My approach normally is to use autoload classes, so we might have something like this...

# file media.info
...
files[] = includes/MediaVariable.inc

# file includes/MediaVariable.inc
class MediaVariable {
  static function Get($variable) {
    ...
  }
}

# file media.module
function media_admin_paths() {
  ...
  $dialog_theme = MediaVariable::Get('dialog_theme');
  ...
}

That way we're achieving the same result, while Drupal, not the module, is dealing with file management.