Updated guidance on avoiding overflow, and explained the security implications of a few compiler flags.

Updated for Xcode 7.3 with -fsanitize and address sanitizer information.

Added information about non-executable stacks and heaps, address space layout randomization, injection attacks, and cross-site scripting.

Made minor typographical fixes.

Fixed minor errors throughout.

Updated for OS X v10.7.

Added security guidelines.

Added article on validating input--including the dangers of loading insecurely stored archives--and added information about the iOS where relevant.

New document that describes techniques to use and factors to consider to make your code more secure from attack.