added place for mersenne solution in eratostenes, renaming zad1→zad1i2

asdzes2zad1i2eratostenes_mersenne/main.c

@@ -43,7 +43,7 @@ void doSE()
 
 #define FILL_CHAR '-'
 
-int main()
+void do_and_print_eratostenes()
 {
     doSE();
     int i;
@@ -66,5 +66,15 @@ int main()
         }
     }
     putchar('\n');
+}
+
+void do_and_print_mersenne()
+{
+}
+
+int main()
+{
+    do_and_print_eratostenes();
+    do_and_print_mersenne();
     return 0;
 }