Subclassing FlutterAppDelegate is not required for real-world apps, but
it's what 'flutter create' generates, and applies the default behaviours
that most real-world apps will want.
As of Xcode 7, Apple recommends setting the bundle identifier in the
PRODUCT_BUNDLE_IDENTIFIER build variable and setting CFBundleIdentifier
to that variable in Info.plist.
As of Xcode 8, CLANG_WARN_INFINITE_RECURSION and CLANG_WARN_SUSPICIOUS_MOVE
are recommended settings.
This patch changes the default `flutter create` command to generate a
HelloServices-style app on iOS. As a consequence, the Atom integration now
fully works with HelloServices.
