(WIP) Demonstration of what could be a framework for SettingsModel types

Since SettingsModels do not have a setValue(Object) method, we need to find
a hopefully clean way to do this. This particular idea works with a Service
and SettingsModelTypePlugins which are discovered at Runtime by Scijava.
(WIP) some source locations, because they are the same for everybody else.

Might be useful. This commit will be overriden by a rebase and forcepush anyway
some day.