Minor modifications for Django 1.5.x and 1.4.x backward-compatibility.

Added new sample project.
Improved documentation.
Refactored CSS selector for inlines that are sortable.

sample_project/templates/index.html

@@ -1,9 +0,0 @@
-<!DOCTYPE html>
-<html lang="en">
-    <head>
-        <title>AdminSortable Test Project</title>
-    </head>
-    <body>
-        
-    </body>
-</html>