channels: replaced bugged lists with ssh_list

(cherry picked from commit 6d8bb956c5)

Conflicts:

	src/channels.c
	src/session.c

src/misc.c

@@ -377,6 +377,8 @@ struct ssh_list *ssh_list_new(){
 
 void ssh_list_free(struct ssh_list *list){
   struct ssh_iterator *ptr,*next;
+  if(!list)
+    return;
   ptr=list->root;
   while(ptr){
     next=ptr->next;
@@ -387,9 +389,19 @@ void ssh_list_free(struct ssh_list *list){
 }
 
 struct ssh_iterator *ssh_list_get_iterator(const struct ssh_list *list){
+  if(!list)
+    return NULL;
   return list->root;
 }
 
+struct ssh_iterator *ssh_list_find(const struct ssh_list *list, void *value){
+  struct ssh_iterator *it;
+  for(it = ssh_list_get_iterator(list); it != NULL ;it=it->next)
+    if(it->data==value)
+      return it;
+  return NULL;
+}
+
 static struct ssh_iterator *ssh_iterator_new(const void *data){
   struct ssh_iterator *iterator=malloc(sizeof(struct ssh_iterator));
   if(!iterator)