Code review comment for lp:~vrruiz/gallery-app/autopilot-app-class

Victor, I'm sorry it took so long to make this review. You will likely have to merge with trunk now.
I'll try harder to make the reviews the same day. But next time I won't make soon a review you request please keep pinging me. I'll owe you a beer for every day you wait :)

For the gallery and apps developers: this change seeks to make it easier for us to test multiple applications at the same time. On its own, it just seems like a huge branch not really useful, and now you will have to call something like self.app.main_view instead of just self.main_view. But it makes a lot of sense when you see a test like this:

address_book = AddressBook.launch()
add_contact_page = address_book.main_view.go_to_add_contact()
add_contact_page.click_contact_image()
gallery_app = GalleryApp()
gallery_app.main_view.pick_image(...)
add_contact_page.main_view.fill_form(...)
add_contact_page.save()

For that we need to move the app helpers out of the test cases because there's no nice way to make a test case that inherits from both the base test cases in address book and gallery.