Add missing header, silence warning. Should fix #292.

darwin/Platform.c

@@ -21,6 +21,7 @@ in the source distribution for its full text.
 
 /*{
 #include "Action.h"
+#include "SignalsPanel.h"
 #include "CPUMeter.h"
 #include "BatteryMeter.h"
 #include "DarwinProcess.h"
@@ -226,5 +227,6 @@ void Platform_setMemoryValues(Meter* mtr) {
 }
 
 void Platform_setSwapValues(Meter* this) {
+   (void) this;
 }
 

darwin/Platform.h

@@ -11,6 +11,8 @@ in the source distribution for its full text.
 */
 
 #include "Action.h"
+#include "SignalsPanel.h"
+#include "CPUMeter.h"
 #include "BatteryMeter.h"
 #include "DarwinProcess.h"