Integrate the splash page into the general layout

* Cleanup the CSS
* Fix more views then you have fingers and toes
* Introduce position(weight) for sponsor levels
* Fix bootstrap/datatable integration

app/models/sponsorship_level.rb

@@ -2,5 +2,6 @@ class SponsorshipLevel < ActiveRecord::Base
   attr_accessible :title, :conference_id
   validates_presence_of :title
   belongs_to :conference
+  acts_as_list scope: :conference
   has_many :sponsors
 end