GUI - Angular:: More sample code; this time, services.

Change-Id: I91422074870722e6a58b096d411e64b5a46c7cc0
diff --git a/web/gui/src/main/webapp/_sdh/ng-examples/ch05-01-need-for-service-app.js b/web/gui/src/main/webapp/_sdh/ng-examples/ch05-01-need-for-service-app.js
new file mode 100644
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+++ b/web/gui/src/main/webapp/_sdh/ng-examples/ch05-01-need-for-service-app.js
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+// ch05-01-need-for-service-app.js
+
+angular.module('notesApp', [])
+    .controller('MainCtrl', [function () {
+        var self = this;
+        self.tab = 'first';
+        self.open = function (tab) {
+            self.tab = tab;
+        }
+    }])
+    .controller('SubCtrl', [function () {
+        var self = this;
+        self.list = [
+            {id: 0, label: 'Item 0'},
+            {id: 1, label: 'Item 1'}
+        ];
+
+        self.add = function () {
+            var n = self.list.length;
+            self.list.push({
+                id: n,
+                label: 'Item ' + n
+            });
+        }
+    }]);
+
+/*
+ NOTE: When we use controllers, they are instances that get created and
+       destroyed as we navigate across the application. Any state they
+        hold is temporary at best, and cannot be communicated to other
+        controllers.
+
+        That's why we'd use "services" instead.
+ */