Closes (PR) #726 : Error checking to the add section modal

 - add padding-bottom to the modal
 - add error checking to the modal
 - add remote requests to do not refresh the webpage
 - change location of select from _student_form to a partial
 - add rjs files to interact with the modal and the select sections
Add Rubymine folder to gitignore
Revert "Add Rubymine folder to gitignore"

This reverts commit a753ff6ef864b8b7a3427ef1a7d64f6db5502a9b.
Closes #1077: add link to directly go to submission

 - addition of a link and its translation
 - small indentation in _list_manage
 - sorry for 80 chars, I can't seem to do better...