Implement simplified commercials workflow

It's now possible to simply enter the url of the third party provider to enter a commercial.

config/config.yml.example

@@ -9,12 +9,6 @@ defaults: &defaults
   #errbit_key: See config/secrets.yml
   #errbit_host: errbit.exmaple.com
   # These are the currently supported commercial types for conference and events
-  commercial_types: { youtube: 'YouTube',
-                           slideshare: 'SlideShare',
-                           flickr: 'Flickr',
-                           vimeo: 'Vimeo',
-                           speakerdeck: 'Speakerdeck',
-                           instagram: 'Instagram' }
 
   # If you want to use iChain to handle registration and authentication enable the next lines
   authentication:

config/routes.rb

@@ -26,7 +26,8 @@ Osem::Application.routes.draw do
       resource :contact, except: [:index, :new, :create, :show, :destroy]
       resources :photos, except: [:show]
       resource :schedule, only: [:show, :update]
-      resources :commercials, except: [:show]
+      get 'commercials/render_commercial' => 'commercials#render_commercial'
+      resources :commercials, only: [:index, :create, :update, :destroy]
       get '/stats' => 'stats#index'
       get '/dietary_choices' => 'dietchoices#show', as: 'dietary_list'
       patch '/dietary_choices' => 'dietchoices#update', as: 'dietary_update'
@@ -89,7 +90,8 @@ Osem::Application.routes.draw do
 
   resources :conference, only: [:index, :show] do
     resources :proposal do
-      resources :commercials, except: [:show, :index]
+      get 'commercials/render_commercial' => 'commercials#render_commercial'
+      resources :commercials, only: [:create, :update, :destroy]
       resources :event_attachment, controller: 'event_attachments'
       member do
         patch '/confirm' => 'proposal#confirm'