Changed path name to  ToDoApp 

Changed path name from ToDoJS to ToDoApp for window.location.href value. This will make the project pages work as it uses repository name(ToDoApp) for file path.
Changed pathname to ToDoApp

Changed path name from,ToDoJS to ToDoApp for window.location.href property because project pages use the repository name for finding the appropriate pages.
Added alert for save button
Rename TodoPage.html to ToDoPage.html
Merged gh-pages with master