MS DC Pull out stream post logic into own class

public/javascripts/app/pages/framer.js

public/javascripts/app/templates/stream-element.handlebars

public/javascripts/app/views/post_view.js

public/javascripts/app/views/stream_object_view.js

public/javascripts/app/views/stream_post_views.js

public/javascripts/app/views/stream_view.js

spec/javascripts/app/views/post_view_spec.js

spec/javascripts/app/views/stream_post_spec.js