add initial Hello World website
- add text/html content type to returned document
- add routes
change selected tab when navigating
finished demo for: initialize angular application, mvc model, two-way binding
refactoring labels
refactoring
change the implementation approach for demo: don't rely on node.js in server side to allow audience can run the demo app in any environment they like (e.g in IIS)
remove node.js server side implementation
no need to depend on $timeout on Hello World demo