Merge remote-tracking branch 'upstream/master'
Moves pjaxload class for menu items from template to here.

* Now Start Trading link is not loaded by the pjax lib but is
  manually loaded by us using pjax. All other links still use the
  class pjaxload
* renames update_trade_urls to register_dynamic_links.
Merge remote-tracking branch 'arun/master'