Add visual cue when moving draggable item over droppable item,

ie. breadcrumb and filenameTd

apps/files/css/files.css

@@ -828,3 +828,7 @@ html.ie8 #controls .button.new {
 .app-files .actions .button.new .icon {
 	margin-bottom: 2px;
 }
+
+.canDrop {
+  background-color: rgba(255, 255, 140, 1);
+}

apps/files/js/breadcrumb.js

@@ -133,7 +133,8 @@
 					drop: this.onDrop,
 					over: this.onOver,
 					out: this.onOut,
-					tolerance: 'pointer'
+					tolerance: 'pointer',
+					hoverClass: 'canDrop'
 				});
 			}
 

core/css/styles.css

@@ -856,7 +856,7 @@ span.ui-icon {float: left; margin: 3px 7px 30px 0;}
 div.crumb {
 	float: left;
 	display: block;
-	background: url('../img/breadcrumb.svg') no-repeat right center;
+	background-image: url('../img/breadcrumb.svg') no-repeat right center;
 	height: 44px;
 	background-size: auto 24px;
 }