Add class that reads and writes a todo.txt file.

TodoFile.py

+"""
+This module deals with todo.txt files.
+"""
+
+import Todo
+
+class TodoFile(object):
+    """
+    This class represents a todo.txt file, which can be read from or written
+    to.
+    """
+
+    path = ""
+    def __init__(self, p_path):
+        self.path = p_path
+
+    def read(self):
+        """ Reads the todo.txt file and returns a list of todo items.  """
+        todos = []
+
+        todofile = open(self.path, 'r')
+
+        for line in todofile:
+            todos.append(Todo.Todo(line))
+
+        todofile.close()
+        return todos
+
+    def write(self, p_todos):
+        """
+        Writes all the todo items in the p_todos array to a todo.txt file.
+        """
+
+        todofile = open(self.path, 'w')
+
+        for todo in p_todos:
+            todofile.write(todo.src + "\n")
+
+        todofile.close()