Move service migration from app to service extension
Adjust services extension

* Add short_content to services
* Add color to services, which can change box border and icon color
* Add icon to services, which can specify font icon
* Remove image from services
* Update admin UI
add validation to number in staff
add image version to images
add image version to images tab
set image size and add methods that return image per size's url
add image_url method in staff.rb that return box size url
Fix image_url when image is blank
restore small, medium, large in refinery image configure
abstract image extension methods to image_ext.rb from plugins
add email valid to staff
change hue to light blue
change background color
Replace liquid editor code with more powerful new one

* Remove old codemirror code and replace with gem
* Add a more powerful liquid mode for codemirror
change staff UI to expandable
Fix bug - when pressing "save & continue editing" button the codemirror content is notsaved
refactor css about maxi
Merge branch 'liu-dev' into refinerycms
add padding-left 10px to .icon in base.sass
Merge branch 'liu-dev' into refinerycms