[ann] spotter processors as settings

We now have a new little feature in Spotter. Take a look:



Basically, you will get a setting for each processor defined in the image. This happens dynamically. If you disable the setting, the processor will not be available anymore.

Please give this a try and let us know what you think.

We would also like a code review related to the way we deal with dynamic settings. Right now, the magic is done in GTSpotterExtensionSettings (this is real magic - read the class comment), but the current solution relies on a doesNotUnderstand: to maintain the list of disabled processors. I would more prefer it if we could create a DynamicSettingDeclaration that would be able to pass arguments to one central selector.