Merge pull request #59 from SwiftyJSON/develop

Add iOS Example, Fix #57
Update README.md
Change enum JSON to strut JSON and Add literal convertible protocol
Update the test case and Add literal convertible tests
Update example
Add subscript tests
Add printable tests
Add sequence type tests
Add comparable tests
Add number setter
Add number and string tests
Update subscript's error
Add Dictionary and Array tests
Change tests files name
Merge branch 'master' into develop
Update README.md
Update README.md
Update README.md
Update error's printable