[atv2] - added substrate.h - needed for hooking methods and ivars at runtime
[atv2] - bump seatbelt unlock patch for patching ios6.1 binary
[atv2/packaging] - on postinst copy our app icon to /Applications/AppleTV.app/com.apple.frontrow.appliance.xbmc\@720p.png - needed for ios6
[atv2] - fix darwinutils - we can't rely on the class name "XBMCAppliance" because its now generated at runtime. This means the NSBundle functions on that class won't return our appliance bundle but the mainbundle (AppleTV.app) which would be wrong - instead use our new real obj-c class "XBMCATV2Detector" which is correctly attached to our appliance bundle.
[atv2] - add a missing key to our atv2 - info.plist
[atv2] - forward declare BRWindow in iosscreenmanager
[atv2] - rewrite the XBMCAppliance and XBMCController for using obj-c runtime class definition and hooking. This is needed for supporting atv2 on ios6 (see the comments in the impl.)