Speed fix in backbone js
My synchronous ajax calls for file size and number meant the more datasets there were, the longer a page seized up in the backbone javascript loading
This makes the calls asynchronous and some jquery setting of the backbone.js badges that display stats instead of backbone.js handling it (I think I'll remove backbone.js later..)
Added some code commenting
Merge pull request #265 from grischa/master

Bug fix for Issue https://github.com/mytardis/mytardis/issues/262
Merge pull request #264 from steveandroulakis/backbone-js-speedfix

Dataset list causing browser to seize up fix