CComponents: implement scroll functionality into CComponentsForm

CComponentsForm provides page scroll if found more
than one pre defined page and is working with all derivated sub classes from CComponentsForm .

Pages are defined with setPageNumber(0...n) in items (1st page = 0). The item page number property is
defined in variable cc_page_number. The highest page number sets the
count of pages inside container to required value. Thats compellingly!

To show a page, we can use setCurrentPage(0...n ) and paintCurPage() or use directly paintPage(0...n).
Note: global paint() will show the current page. Default page is 0 (as first).
Use setCurrentPage(0...n) to change this before first call of paint().
Note: In CComponentsWindow class, these methods are applied to window body.

For examples, take a look into CTestMenu

src/gui/test_menu.h

@@ -53,6 +53,7 @@ class CTestMenu : public CMenuTarget
 		CComponentsFrmClock *clock ,*clock_r;
 		CComponentsChannelLogo* chnl_pic;
 		CComponentsExtTextForm* text_ext;
+		CComponentsScrollBar* scrollbar;
 		int width, selected;
 
 		int showTestMenu();