Merge branch 'redesign_creating_lessonplan' of github.com:twers/re-education into use_qiniu_images_service
import qiniu service into project. Qiu
use javascript base64 encode for qiniu token generation. Qiu
add request token meta tag in head. Qiu
integrate jquery uploader plugin to qiniu service. Qiu
use thumbnail and medium size image to optimise performance. Qiu
add upload progress in adding task. Qiu
fix bug that clear the content of task after delete task. Qiu
fix the auto height of editor.
add loading image placeholder of image. Qiu
Merge pull request #49 from twers/use_qiniu_images_service

Use qiniu images service