add link to new article in article#index
update vote_spec to validate voter_id in scope of voteable_id
update validations in Vote to check unqi voter_id in scope for voteable_id
add ability to post article for current user
update vote logic in commetns_controller
Merge remote-tracking branch 'origin/user_post_article' into one_vote_per_user_per_thing_xiran
update vote logic in articles_controller
update articles polymorphic association
Merge pull request #33 from ospreys-2014/one_vote_per_user_per_thing_xiran

One vote per user per thing xiran