Changed several of the Cocoa formatters to match the output style that Xcode uses internally to provide summaries
This has been done for those summaries where the difference is only cosmetic (e.g. naming things as items instead of values, ...)
The LLDB output style has been preserved when it provides more information (e.g. telling the type as well as the value of an NSNumber)

Test cases have been updated to reflect the updated output style where necessary

llvm-svn: 152592