add tags in configus
add helper method for tags
improve configus and helper method
add method to decorator, add showing at view
improve decorator
show tags in form for standards
Merge branch 'feature/tags_and_autocorrect' into develop

* feature/tags_and_autocorrect:
  show tags in form for standards
  improve decorator
  add method to decorator, add showing at view
  improve configus and helper method
  add helper method for tags
  add tags in configus
add gem pdfkit
add pdf::standards controller
make able to get pdf only from pdf/standards
make pdf/stadnards/index.pdf
make show view for pdf/standards/show.pdf
generate only several standards in pdf
add link to generate pdf
add links
make modal box, add it
add checkbox 'all'
add translations
improve js for pdf modal box
improve pdf showing link to generation pdf