Revert "Allow expired events in the grid and style with phonecian purple"

This reverts commit a103a62faf. Users
complained that persistent expired events was not the right choice for
them.

Conflicts:
	lib/riemann/dash/public/views/grid.js

lib/riemann/dash/public/views/grid.js

@@ -385,7 +385,11 @@
   
   // Accept an event.
   Grid.prototype.update = function(e) {
-    this.add(e);
+    if (e.state === "expired") {
+      this.remove(e);
+    } else {
+      this.add(e);
+    }
   };
 
   Grid.prototype.reflow = function() {

lib/riemann/dash/views/css.scss

@@ -176,10 +176,6 @@ html,table {
   background: $orange;
   color: #000;
 }
-.state.expired {
-  background: $purple;
-  color: #000;
-}
 
 .view .query {
   display: block;