Merge pull request #471 from zhanghongyan/dev

Dev
Merge branch 'dev'
Merge branch 'dev'
Merge branch 'dev'
Merge branch 'dev'
Merge branch 'dev'
Merge branch 'dev'
Merge branch 'dev'
添加timer功能块，优先采用animation frame.
Merge pull request #554 from linlingyu/dev

[Feature] 增加plugin接口
已基本完成，还待优化
已基本完成，还待优化
完成1/4左右的测试用例
Merge pull request #555 from liaoxuezhi/dev

fx功能，待测试用例完善
测试用例完成！
修改bug
Merge remote-tracking branch 'upstream/master' into dev
Merge remote-tracking branch 'upstream/dev' into dev
改用plugin接口，对底层dom扩展
添加inlieBlockNeedsLayout support检测