Update project tab/indent settings to match existing code.

This ensures devs with different global Xcode settings use the correct
style.
Extend the selector engine protocol, passing along all registered 
windows to engines that support the enhanced protocol.

Selector engines should implement this new method by returning all
matching views in any of the given windows.
Keep the compiler happy.
Ensure we only call the new protocol method and import the UIApplication
category on iOS builds only.
Merge pull request #250 from lukeredpath/pass-windows-to-selector-engines

Pass all windows to selector engines