Template event handlers and error view

New features

• Defining event handlers in a template, e.g. (click)="window.alert('Hello world');"
• Setting an error view to handle all paths which are not mapped to any view
• Automatic loading of web components polyfill

Fixes

• Applications can now be serialized and deserialized properly
• Special characters in URLs are handled properly
• RouterConfiguration getParentView changed to return Optional instead of null

Demos

• The web site demo was updated to use an error view

New tutorials

• Defining an Error View

All changes