Xcode doesn't see to add a UIRequiredDeviceCapabilities = 'watch-companion'
anymore for watchos apps/extensions, not even when setting the deployment
version to 2.0.
This makes watchOS 2 apps launch in the simulator again.
MSBuild compares what is in FileWrites with the Outputs of the target
and any file that exists in FileWrites but *doesn't* exist in Outputs
gets deleted with the assumption that it is no longer needed via the
IncrementalClean MSBuild target.
Since these tasks cannot know what the outputs will be until the task
is run, we cannot use FileWrites.
Vincent Dondain
Rolf Bjarne Kvinge
Jeffrey Stedfast