addAdContainerToViewInViewController doesn't recreate adapter instances after destroyAllAdBanners

In my app I need to show and hide the banners if certain conditions are met. If I call `addAdContainerToViewInViewController`, then `destroyAllAdBanners` and then `addAdContainerToViewInViewController` again the banners won't show up (the second time).

I fixed the issue and a couple of Xcode related issues. Note that Github forced me to delete AdMob submodule because it doesn't exist anymore and I don't know where I can find it.