Move stupidtable.js into application.js.

Fixes this javascript error:

    Uncaught TypeError: $(...).stupidtable is not a function

on these pages:

* http://safebooru.donmai.us/reports/user_promotions
* http://safebooru.donmai.us/reports/contributors
* http://safebooru.donmai.us/reports/janitor_trials

...due to stupidtable.js not loading.

app/assets/javascripts/application.js

@@ -5,6 +5,7 @@
 //= require jquery-ui-autocomplete-custom.js
 //= require jquery.storageapi.js
 //= require ugoira_player.js
+//= require stupidtable.js
 //= require rails.js
 //= require common.js
 //= require_tree .

app/views/reports/contributors.html.erb

@@ -36,7 +36,6 @@
 <% end %>
 
 <%= content_for(:html_header) do %>
-  <%= javascript_include_tag "stupidtable" %>
   <script type="text/javascript">
     $(function() {
       $("#sortable").stupidtable().on("aftertablesort", function() {

app/views/reports/janitor_trials.html.erb

@@ -47,7 +47,6 @@
 <% end %>
 
 <%= content_for(:html_header) do %>
-  <%= javascript_include_tag "stupidtable" %>
   <script type="text/javascript">
     $(function() {
       $("#sortable").stupidtable().on("aftertablesort", function() {

app/views/reports/user_promotions.html.erb

@@ -40,7 +40,6 @@
 <% end %>
 
 <%= content_for(:html_header) do %>
-  <%= javascript_include_tag "stupidtable" %>
   <script type="text/javascript">
     $(function() {
       $("#sortable").stupidtable().on("aftertablesort", function() {