Clean up the mess in our development Yii version!

Things to do:

1. Remove usage of $this->yii and $this->controller from the actions and instead use Yii::app and $this->getController() respectively.
2. Remove $dbprefix usage from all queries and instead wrap table names with curly braces.
3. Format code with respect to LimeSurvey Coding guidelines.
4. Implement Survey_Common_Action::_renderWrappedTemplate() in all the administration actions.
5. Properly implement Survey_Common_Action::css_admin_includes() and Survey_Common_Actions::js_admin_includes() (migrate them from AdminController) in all the administration actions.
6. Standardize code across all the actions (especially run method).