Tested with iOS 7.1 on an iPad 3
- Dynamic registrar needs to ignore new CBManager base class;
- CGImageMetadataTag.Value returns a mutable array on iOS10;
- MPMediaItem properties needed 9.2 / 10.0 check;
- MSMessage not available before Xcode 8;
- Metal not available before Xcode 6;
- MetalPerformanceShaders not available before Xcode 7;