adds rake task for repocess file thumbnails [fixes SCI-831]
adds rake task for repocess file thumbnails [fixes SCI-831]

Ducz0r/scinote-web,mlorb/scinote-web,mlorb/scinote-web,Ducz0r/scinote-web,Ducz0r/scinote-web,mlorb/scinote-web