Initial commit for Vaadin 7.2
Added components

  Added a Label
  Added a TextField
  Added a PasswordField
Changed the vertical layout to a horizontal layout
Changed the horizontal layout to a form layout
Added a margin to the layout
Set size on the login field
Set height on the dynamically added label
Added a page title via the API
Change the way to add the page title from API to annotation
Extracted the servlet configuration into a dedicated class
Refactored the listener to a top-level abstraction
Extracted UI component into its own class
Changed from a fixed FormLayout to a CustomComponent
Added a new MainScreen component
Implemented a basic switch screen listener
Added preserve on refresh on UI
Added a simple notification after authentication
Implemented a simple authentication logic and the relevant error notification
Store the user name at login and display it on the main screen
Updated the main screen with needed components