voting authentication ui
add useful link
remove redundant code
refactoring

removed some unneeded DRYness
set argument users
refactor helper methods
removed unused method
make voting actually change the score again

authorization is not properly implemented yet at the controller
level: an attacker can just load the appropriate url to get
as many votes as he wishes
hopefully fix for heroku non being able to build rdiscount
disable vote for not logged in users

temporary measure till I enable better anon user handling