3.5

Added

• Boxed values now actually formally conform to relevant protocols (as reported by confromsToProtocol:)

Fixed

• Removed some optimizations in makeBlock that could cause unexpected block move
  instead of copy when reusing block pointers
• Added <exception> header include to XCTestUtil.h that is now required on newer Xcodes
• Making BoxUtil.h not rely on std::filesystem which is not available on older Apple
  platforms.