+Format of nodes
+----------------
+A node is composed of the u8 fields param0, param1 and param2.
+
+if map format version <= 23:
+ The content id of a node is determined as so:
+ - If param0 < 0x80,
+ content_id = param0
+ - Otherwise
+ content_id = (param0<<4) + (param2>>4)
+if map format version >= 24:
+ The content id of a node is param0.
+
+The purpose of param1 and param2 depend on the definition of the node.
+
+The name-id-mapping
+--------------------
+The mapping maps node content ids to node names.
+