Add function def of sinf,cosf and tanf. Symbian is missing these functions in...

Add function def of sinf,cosf and tanf. Symbian is missing these functions in its math.h file, but should it be located some where else?

src/bonus/bonus.cpp

@@ -40,6 +40,12 @@
 
 #include <math.h>
 #include <string.h>
+
+#ifdef __SYMBIAN32__
+extern float cosf (float);
+extern float sinf (float);
+extern float tanf (float);
+#endif
 
 #define PI 3.141592f