Remove unused class.

django_starfield/defaults.py

+STARFIELD_COLOUR = '#f5b301'
+STARFIELD_CODEPOINT = '2605'
+STARFIELD_STARS = 5

django_starfield/static/django_starfield.css

@@ -65,12 +65,3 @@
 {
     filter: grayscale(0);
 }
- 
-.acidjs-rating-disabled
-{
-    opacity: .50;
-     
-    -webkit-pointer-events: none;
-    -moz-pointer-events: none;
-    pointer-events: none;
-}