Fix a typo
Add missing code format
Merge pull request #215 from johnnywjy/master

Fix a typo and add missing code format
Reviewed
Merge branch 'master' of github.com:objccn/articles
publish 14-4
Prepare for gitbook
Finish 14-3's translation
fix a little mistake.
Merge pull request #217 from WilliamZang/patch-1

fix a little mistake.
Fix 6-1
Merge pull request #216 from oa414/issue-14-3-oa414

完成14-3翻译
Update submodule
finish issue-14-5 first draft
Merge branch 'new/issue-14-5-crazycatcher'
Create issue-14-1-ckitakishi.md
Update issue-14-1-ckitakishi.md
Review 14-3 ok
Merge pull request #218 from CrazyCatcher/master

完成 14-5 初稿翻译
Merge pull request #220 from objccn/review/14-3-onevcat

Review/14 3 onevcat