Adding class names in a wrapping div 
Adding class names in a wrapping div 

In the form() method added class names ccm-attribute, ccm-attribute-image-file. Added to wrapping div because it didn't seem possible to add them to the file selector.

Former-commit-id: 1e364161ad058a2df2043e403a1c214eb9e6d610
Former-commit-id: 836b534271942c57c4dce8b8a3e894bbba34eb6a
mlocati/concrete5,hissy/concrete5,a3020/concrete5,jaromirdalecky/concrete5,concrete5/concrete5,acliss19xx/concrete5,MrKarlDilkington/concrete5,haeflimi/concrete5,concrete5/concrete5,mlocati/concrete5,triplei/concrete5-8,mainio/concrete5,triplei/concrete5-8,biplobice/concrete5,hissy/concrete5,deek87/concrete5,KorvinSzanto/concrete5,jaromirdalecky/concrete5,KorvinSzanto/concrete5,mainio/concrete5,rikzuiderlicht/concrete5,deek87/concrete5,deek87/concrete5,acliss19xx/concrete5,biplobice/concrete5,acliss19xx/concrete5,deek87/concrete5,mainio/concrete5,concrete5/concrete5,haeflimi/concrete5,hissy/concrete5,triplei/concrete5-8,hissy/concrete5,jaromirdalecky/concrete5,concrete5/concrete5,mlocati/concrete5,MrKarlDilkington/concrete5,rikzuiderlicht/concrete5,haeflimi/concrete5,KorvinSzanto/concrete5,rikzuiderlicht/concrete5,haeflimi/concrete5,olsgreen/concrete5,biplobice/concrete5,a3020/concrete5,MrKarlDilkington/concrete5,jaromirdalecky/concrete5,olsgreen/concrete5,mlocati/concrete5,olsgreen/concrete5,biplobice/concrete5