#2 auto-reload feature

[Meinte Boersma]

Create a "developer mode" which is configured in WebApplicationServer, off by default.

Switching it on makes every response served execute an Ajax request with a specific servlet which is signalled when the model is updated (through saving of the file). The response to the Ajax request is only sent when the signal comes true and the model is updated (re-loaded) and consists of a redirect URL. This "reloads" the current page or some other appropriate one in case the page doesn't exist in the model anymore or if it is impossible to serve the same page for some other reason.