vaadin/flow 8.0.0.alpha9 on GitHub

Vaadin Flow 8.0.0.alpha9

New Features:
- ⧉ Do not serialize VaadinSession by default in development. PR:11304. Ticket:11151
  Avoids writing VaadinSession to the HTTP session when the controlling properties are set (devmode + parameter). For implementation reasons, something must be serialized so only a boolean is written and these kind of "not actually serialized" sessions are removed when loading them after deserialization. This makes it unnecessary to login again to application when developing it with live reload tools and the authentication data is stored in the HttpSession.
Fixes:
- ⧉ Provide info about navigation target in NotFoundException. PR:11309. Ticket:7071
- ⧉ Use ServletContext classloader as a default classloader for service. PR:11308. Ticket:4367
- ⧉ Always use unix convention for the path. PR:11326. Tickets:11220, 11325
⧉ All changes