Separate array and object extensions from id3_tree

lib/core_extensions/object.rb

@@ -0,0 +1,9 @@
+class Object
+  def save_to_file(filename)
+    File.open(filename, 'w+') { |f| f << Marshal.dump(self) }
+  end
+
+  def self.load_from_file(filename)
+    Marshal.load(File.read(filename))
+  end
+end