Bug 1094151 - Write a test to install & launch a packaged app from the M...

...arketplace
Yeah, in this case I'm using the manifest url to launch the app, because of bug 1077446.
"Dev" and "Stage" marketplace apps are also called "Marketplace", so I'm not able to launch the Dev Marketplace app by name, currently.
Base.launch() is a little weird here, I think. I need to add a bogus name, then it will use the manifest to launch the app. It would be nicer if I wouldn't need to add the bogus name at all.

I'm not exactly sure what you want here. I can remove the "if app_name:" thing, then it will use "None" apparently for self.name. I would think it just to be better when a consumer would not provide a name.
I think Base.lauch() should be improved to allow it not to be provided a name when a manifesturl is given.