CComponentsItem: move initBodyGradient() into base class

This provides functinality for all sub classes too


Origin commit data
------------------
Commit: 581405e076
Author: Thilo Graf <dbt@novatux.de>
Date: 2014-09-20 (Sat, 20 Sep 2014)

src/gui/components/cc_frm_header.h

@@ -93,8 +93,6 @@ class CComponentsHeader : public CComponentsForm
 		void initCaption();
 		///sub: init context button object
 		void initButtons();
-		///sub: init color gradient
-		void initGradient();
 
 	public:
 		enum