Merge pull request #4 from yuxiangq/master

add a new callback
Merge pull request #6 from yuxiangq/master

support block
Update README.md
test
Merge branch 'master' of https://github.com/JackTeam/XHImageViewer
reset spec file
1.修复代码风格 2.删除资源文件错误定位 3.添加上下工具条的功能
update podspec v0.1.4
删除占用空间的gif图
Update README.md