GUAC-326: Add notification for mouse emulation type change. Use it to signal completed downloads while we're at it.

guacamole/src/main/webapp/styles/client.css

@@ -639,4 +639,18 @@ p.hint {
     right: 0;
     bottom: 0;
     opacity: 0;
-}
+}
+
+.notification.message {
+    background: #DFD;
+    animation: fadein 0.125s linear, fadeout 2s 3s linear;
+    -webkit-animation: fadein 0.125s linear, fadeout 2s 3s linear;
+}
+
+.notification.message .caption {
+    vertical-align: middle;
+    white-space: normal;
+    overflow: hidden;
+    text-overflow: ellipsis;
+}
+