Fix version and tag in podspec.
Fix license field in podspec.
Use GitHub URL instead of URL to blog post for the homepage URL of FileMD5Hash.
Minor cosmetic changes to podspec file.
New API for FileMD5Hash.
  - Objective-C API to simplify eventual usage of this with ARC;
  - rename files to FileHash; I expect to add more methods for other types of hashes;
  - stop using goto or any form of early return.
Modernize sample applications.
Rename Mac folder and target as "OS X".
Update copyright.
Rename folder "Common" as "Library".
Making logic for creating cryptographic hashes more generic, and add SHA1 and SHA512 APIs.
Upgrade to new Xcode recommended settings.
Move iOS and OS X folders in a new folder named "Sample Client".
Bump up to version 2.0.0.