CComponentsHeader/CComponentsFooter: prevent crash on changed font settings

Default fonts for header and footer must be handled too.
After font settings changes these objects could be invalid.
Default fonts have invalid pointers after font changes too. Extra reset is required.


Origin commit data
------------------
Commit: b98319cb91
Author: Thilo Graf <dbt@novatux.de>
Date: 2016-12-29 (Thu, 29 Dec 2016)

src/gui/components/cc_frm_footer.h

@@ -84,6 +84,9 @@ class CComponentsFooter : public CComponentsHeader
 		///property: set font for label caption, see also setButtonFont()
 		Font* ccf_btn_font;
 
+		///init default fonts for size modes
+		virtual void initDefaultFonts();
+
 		///container for button objects
 		CComponentsFrmChain *chain;