Bugtracker #30177 avoid JPATH_COMPONENT_ADMINISTRATOR

Ability to load ContentModelArticle outsides.

Test instruction:
Try to load ContentModelArticle from another extension and use it like:
JModelLegacy::addIncludePath(JPATH_ADMINISTRATOR.'/components/com_content/models', 'ContentModel');
$model = JModelLegacy::getInstance('Article', 'ContentModel', array('ignore_request' => true));
$model->delete($foobar);


Maybe we should rethink the JPATH_COMPONENT_ADMINISTRATOR thing.
For example we are using JPATH_COMPONENT_ADMINISTRATOR on JModelAdmin to add the table-path.
So you can not just use the Model without carring about the table.

Joomlacode: http://joomlacode.org/gf/project/joomla/tracker/?action=TrackerItemEdit&tracker_item_id=30177