Make SampleApp work on iPhone/iOS simulator.

Make SampleApp work on iPhone/iOS simulator.

Several parts to this:

1) The DeviceManager subclass for iOS was rewritten because the base class
changed.

2) Two old samples that rely on hardcoded paths to images are deleted. They hit
assertions in SkImageRef. No one has the required images to run these anyway.

3) argv must be non-NULL.

4) The UI delegate must not be loaded from the NIB for viewDidLoad ordering
reasons. So I removed an IBOutlet link from the window to the splitview
controller in the iPad's NIB file. The split view is attached by the AppDelegate
programmatically.

This doesn't make GPU work. That will come in a later change.

Review URL: https://codereview.appspot.com/6561056/

git-svn-id: http://skia.googlecode.com/svn/trunk@5712 2bbb7eff-a529-9590-31e7-b0007b416f81