Feedback bar for showing response to user actions

Fixes #215

static/css/directives/ui/feedback-bar.css

@@ -0,0 +1,52 @@
+.feedback-bar {
+  position: absolute;
+  top: 0px;
+  left: 0px;
+  right: 0px;
+  z-index: 50;
+  overflow: hidden;
+  text-align: center;
+  height: 42px;
+}
+
+@keyframes flow-down-up {
+    0%   {
+      top: -40px;
+    }
+
+    25%  {
+      top: 0px;
+    }
+
+    75%  {
+      top: 0px;
+    }
+
+    100% {
+      top: -40px;
+    }
+}
+
+.feedback-bar-element {
+  position: relative;
+  top: -40px;
+
+  text-align: center;
+  display: inline-block;
+
+  background: #eee;
+  padding: 10px;
+  border: 1px solid #eee;
+  border-top: 0px;
+
+  animation-name: flow-down-up;
+  animation-duration: 5s;
+}
+
+.feedback-bar .feedback-bar-element.info {
+  background-color: #F0FAFF;
+}
+
+.feedback-bar .feedback-bar-element.warning {
+  background-color: #FFFBF0;
+}