fix for CRM-13374

This will fix the bug mentioned in the issue i.e. now, the "closed" events will also appear in the select box when we create or edit a "CiviCRM Event Information Page" menu item using joomla.
I checked the fix on joomla 2.5.x. It works fine. But, when I tried checking on Joomla 3.x, I found altogether a different bug. The bug was that after creating
"CiviCRM Event Information Page" menu item for a particular event, when I go and click on this menu link in the joomla site, a blank page appears (Event info page is the expected page). I did some debug and found that in civicrm/joomla/sites/civicrm.php, within civicrm_invoke function, "$_GET" was being used to build the $args array(which is required for invoking the respective page."civicrm/event/info" page in our case). The problem is that "$_GET" is not getting populated in Joomla 3.x. I checked online and found some similar issues related to Joomla 3.x like http://www.joomlapolis.com/forum/277-cbsubs-gpl-support/219260-3881-bug-on-cbsubs-content-with-joomla-30-and-sef and http://joomlacode.org/gf/project/joomla/tracker/?action=TrackerItemEdit&tracker_item_id=29540 where people have reported about $_GET not getting populated.

So, I have made the fix by using $_REQUEST to build $args array. The fix is as follows:
https://github.com/ravishnair/civicrm-joomla/commit/556adb35c90eeb15b2394526a9d0a78a474bc7db