Cleaned up usage of linked lists and added missing functionality.

- Added a list_remove_first() which is generally better than list_remove()
  provided you want to remove the first element.
- Added a list_append_list() to append and move all nodes from one list to
  another.

src/util/list.h

@@ -42,6 +42,13 @@ extern void list_clear(struct linked_list*, void (*free_handle)(void* ptr) );
 
 extern void list_append(struct linked_list* list, void* data_ptr);
 
+/**
+ * A special list append that moves all nodes from other_list to list.
+ * The other list will be empty.
+ */
+extern void list_append_list(struct linked_list* list, struct linked_list* other);
+
+
 /**
  * Remove data_ptr from the list. If multiple versions occur, only the first one is removed.
  */
@@ -57,6 +64,12 @@ extern void* list_get_prev(struct linked_list*);
 extern struct node* list_get_first_node(struct linked_list*);
 extern struct node* list_get_last_node(struct linked_list*);
 
+/**
+ * Remove the first element, and call the free_handle function (if not NULL)
+ * to ensure the data is freed also.
+ */
+extern void list_remove_first(struct linked_list* list, void (*free_handle)(void* ptr));
+
 #define LIST_FOREACH(TYPE, ITEM, LIST, BLOCK) \
 		for (ITEM = (TYPE) list_get_first(LIST); ITEM; ITEM = (TYPE) list_get_next(LIST)) \
 			BLOCK