node deletion with connection deletion and signal redistribution implemented

src/signal.h

@@ -4,7 +4,6 @@
 
 #include "datatypes.h"
 #include "moveable.h"
-#include "node.h"
 
 class Signal : public Movable{
 	public:
@@ -14,10 +13,10 @@ class Signal : public Movable{
 	
 	int id = 0;
 
-	Node *next;
-	Node *last;
+	int next;
+	int last;
 
-	Node *start;
+	int start;
 
 	bool at_target = false;
 	int target_node_id = 1;