OS version detection without deprecated API
Use recently added OS version detection to check for HID Manager API availability
Merge branch 'z_osx_clean' of https://github.com/alexey-lysiuk/gzdoom into osx
* update Xcode project

* compatibility with Xcode 3.1
* tabs instead of spaces
+ missing header file
* multi-threaded upscaling using xBRZ algorithm is back