[e4] Perspective TrimBar Contributions are ignored

[laeubi]

I have created the E4 Example project and modified it to use a perspective, then I added a perspective trim bar

Starting the application now looks the same as before even though I'm not sure what should happen I would have expected that something changes.

Looking to references to org.eclipse.e4.ui.model.application.ui.advanced.MPerspective.getTrimBars() I can not see it is actually used anywhere.

@vogella and others as said I'm not completely sure what should happen here, e.g. should a perspective trimbar replace the window trimbar or enhance it? Is there an E3 equivalent and we have simply not implemented this in E4 yet?