[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
[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.)