Initial support for low level ECMA-119 tree.

This only adds the tree creation functions, no sorting and name mangling 
yet. Only plain ECMA-119 supported for now, nor RR, relaxed 
restrictions, etc..

This also adds a little test program.

src/ecma119_tree.h

@@ -0,0 +1,68 @@
+/*
+ * Copyright (c) 2007 Vreixo Formoso
+ * 
+ * This file is part of the libisofs project; you can redistribute it and/or 
+ * modify it under the terms of the GNU General Public License version 2 as 
+ * published by the Free Software Foundation. See COPYING file for details.
+ */
+
+#ifndef LIBISO_ECMA119_TREE_H_
+#define LIBISO_ECMA119_TREE_H_
+
+#include "libisofs.h"
+#include "ecma119.h"
+
+enum ecma119_node_type {
+    ECMA119_FILE,
+    ECMA119_DIR
+};
+
+/**
+ * Struct with info about a node representing a tree
+ */
+struct ecma119_dir_info {
+    /* Block where the directory entries will be written on image */
+    size_t block;
+
+    size_t nchildren;
+    Ecma119Node **children;
+};
+
+/**
+ * A node for a tree containing all the information necessary for writing
+ * an ISO9660 volume.
+ */
+struct ecma119_node
+{
+    /**
+     * Name in ASCII, conforming to selected ISO level.
+     * Version number is not include, it is added on the fly
+     */
+    char *iso_name;
+    
+    // TODO mmm, is this needed? 
+    // or should we compute charset translation on-the-fly?
+    //char *name;      /**< full name, in output charset (UTF-8 for now) */
+    
+    Ecma119Node *parent;
+    
+    IsoNode *node; /*< reference to the iso node */
+
+    enum ecma119_node_type type; /**< file, symlink, directory or placeholder */
+    union {
+        IsoFileSrc *file;
+        struct ecma119_dir_info dir;
+    } info;
+};
+
+/**
+ * 
+ */
+int ecma119_tree_create(Ecma119Image *img, IsoNode *iso, Ecma119Node **tree);
+
+/**
+ * Free an Ecma119Node, and its children if node is a dir
+ */
+void ecma119_node_free(Ecma119Node *node);
+
+#endif /*LIBISO_ECMA119_TREE_H_*/