Renaming “-valueDataForCStringKey:” to “-_valueDataForCStringKey:”.
Renaming “-getAttributeListData” to “-_getAttributeListData”.
Cleanup.
Improving input checking.
Calling “-setData:forKey:” with a nil value will remove the entry.
Adding ARC compatibility.
Prefixing ivars with underscore.
Replacing id with instancetype where appropriate.
Fixing type comparison warning.
Adding convenience methods auto-detecting necessary conversions.
Fixing file headers.
Cleanup.
Adding more convenience methods.
Using NSKeyedUnarchiver instead of old NSUnarchiver.
Fixing NSPropertyListSerialization handling.
Fixing leak.
Converting to to Modern Objective-C Syntax.