Merge pull request #8 from areteCocoa/master

More information about Enumerated Types.
Update README.md

Added removing objects from array
Merge pull request #9 from joelfischerr/patch-1

Update README.md
Update README.md

Like the NSArray example, the NSDictionary example uses a mutable dictionary.
Added examples on how to add and remove objects from the dictionary
Merge pull request #10 from joelfischerr/patch-2

Update README.md
Updated with new NS_ENUM and optional delegate checking.
Merge pull request #12 from bennyguitar/master

Updated with new NS_ENUM and optional delegate checking.