add a javascript sdk link in resource
update the css_sprite
hack
use css sprite in index/docs-index
update ,add a comment
update name
sprite img
Merge remote-tracking branch 'qiniu/master' into 7172_ADD_Javascript_resource

Conflicts:
	static/css/less/_css-sprite.less
	static/css/main.css
	static/image/css-sprite.png
update data
Merge remote-tracking branch 'qiniu/master' into 7172_ADD_Javascript_resource

Conflicts:
	_data/resource.json
	_layouts/homepage.html
Merge pull request #99 from SunLn/7172_ADD_Javascript_resource

add a javascript sdk link in resource