Setup basic Revision History page

Sets up paper_trail tracking in important models

and add conference_id to versions for storing conference_id
of conference related objects  as metadata.This will help in querying
for versions related to conferences.

Fix issues with factories & event types initialization.Import paper_trail testing helpers
Fix bug: Creating an event creates a useless version with event update

Add revert and view changes features to revision history

app/assets/javascripts/application.js

@@ -41,6 +41,7 @@
 //= require osem-schedule
 //= require osem-switch
 //= require osem-bootstrap
+//= require osem-revisionhistory
 //= require osem-commercials
 //= require unobtrusive_flash
 //= require unobtrusive_flash_bootstrap

app/assets/javascripts/osem-datatables.js

@@ -7,6 +7,11 @@ $(function () {
       pagingType: 'full_numbers',
       "lengthMenu": [[25, 50, 100, -1], [25, 50, 100, "All"]]
     });
+
+    $('#versionstable').DataTable({
+      pagingType: 'full_numbers',
+      order: [[ 0, 'desc' ]]
+    });
   });
 });
 

app/assets/javascripts/osem-revisionhistory.js

@@ -0,0 +1,10 @@
+$(document).ready(function() {
+    $('.show-changeset').click(function(){
+        if ($(this).text() == 'View Changes'){
+            $(this).text('Hide Changes');
+        }else {
+            $(this).text('View Changes');
+        }
+        $('#changeset-' + this.id).toggle();
+    });
+});