Adding drag-n-drop feedback to app install.

Change-Id: I82718d930e2121f4e6c8109a89513fa755c18141

@@ -173,3 +173,15 @@
 .dark #application-details-panel .bottom tr:nth-child(even) {
     background-color: #555;
 }
+
+.dropping {
+
+}
+
+.light div.dropping {
+    border: solid 3px deepskyblue;
+}
+
+.dark div.dropping {
+    border: solid 3px deepskyblue;
+}

@@ -407,11 +407,13 @@
 
                 // When an item is dragged over the document
                 var onDragOver = function (e) {
+                    d3.select('#frame').classed('dropping', true);
                     e.preventDefault();
                 };
 
                 // When the user leaves the window, cancels the drag or drops the item
                 var onDragEnd = function (e) {
+                    d3.select('#frame').classed('dropping', false);
                     e.preventDefault();
                 };