添加第四章变量
Merge branch 'master' of github.com:yiyangwang/crazyobjectivec

Conflicts:
	.DS_Store

ch04/ArrayArg/ArrayArg.xcodeproj/project.xcworkspace/xcuserdata/wangyiya
ng.xcuserdatad/UserInterfaceState.xcuserstate

ch04/ArrayElementAry/ArrayElementAry.xcodeproj/project.xcworkspace/xcuse
rdata/wangyiyang.xcuserdatad/UserInterfaceState.xcuserstate

ch04/Recursive/Recursive.xcodeproj/project.xcworkspace/xcuserdata/wangyi
yang.xcuserdatad/UserInterfaceState.xcuserstate