Create a new Dummy-plugin

[Hallbergs]

The Dummy plugin is a great plugin that can be used to get to know the basics of Hajk (for developers). I know of several (including myself) who used the Dummy-plugin to get to know Hajk.

However, the Dummy-plugin lacks some functionality that could be shown (for example the Cookie-handler, the draw/kml-models etc. etc).

I propose that we create a new Dummy-plugin, showing even more of Hajk's functionality. I think that would help new developers.