Fixed tricorn_V3.c to correctly handle complex numbers and add threaded V4 skeleton

Implementierung/tricorn_V4.h

@@ -0,0 +1,5 @@
+#include <complex.h>
+#include <stddef.h>
+#include <math.h>
+#include <sys/types.h>
+void tricorn_V4(float complex  start, size_t width, ssize_t  height, float res, unsigned n, _Bool color, unsigned char* img);