Example 4, generic form-handling app (step 1)

Some initial layout for future application, features serving static files
from a sub-folder + linking css from a diet template.
Example 4, generic form-handling app (step 2)

Adds custom error handler with debug info and enables generation of stack traces
Example 4, generic form-handling app (step 3)

Adds session handling example to the mix, main page is adjusted to show
session if of the visitor and how many times he has visited the page in current session.
Example 4, WIP