add qiniu upload image

i add qiniu uploader, but i just achieve function in another way. like the following.
because the qiniu sdk has some limits. so you need to copy the image url and paste it to the markdown editor, 

![image](https://cloud.githubusercontent.com/assets/4927218/5592179/5f25ae12-91f7-11e4-8a6d-f00d7b6faf68.png)