Made comments a required field
Made comments a required field

- app/views/comments/_add_comment_form.html.erb - Prevent user from
  entering empty comment field

Updates #1449

EBWiki/EBWiki,EBWiki/EBWiki,BOWiki/BOW,BOWiki/BOW,EBWiki/EBWiki,BOWiki/BOW,EBWiki/EBWiki