reduce impact of zapit/frontend_c.h header

down from ~217 files to ~57...

src/driver/record.h

@@ -58,6 +58,7 @@ extern "C" {
 #define TSHIFT_MODE_REWIND	3
 
 class CFrontend;
+class CZapitChannel;
 
 //FIXME
 enum record_error_msg_t

src/gui/components/cc_frm_signalbars.cpp

@@ -31,6 +31,7 @@
 #include <neutrino.h>
 #include "cc_frm_signalbars.h"
 #include <driver/fontrenderer.h>
+#include <zapit/include/zapit/frontend_c.h>
 #include <sstream>
 
 #define SB_MIN_HEIGHT 12

src/gui/components/cc_frm_signalbars.h

@@ -36,7 +36,6 @@
 #include <gui/components/cc_item_progressbar.h>
 #include <gui/components/cc_item_text.h>
 #include <gui/components/cc_text_screen.h>
-#include <zapit/include/zapit/frontend_c.h>
 #include <driver/neutrinofonts.h>
 
 /// Basic class for signalbars
@@ -48,6 +47,7 @@ CSignalBar() and their sub classes based up CComponentsForm() and are usable lik
 CSignalBar() is intended to show signal rate.
 */
 
+class CFrontend;
 class CSignalBar : public CComponentsForm, public CCTextScreen
 {
 	public: