Backward compatibility of 2.x with 4.6

Hello !

It seems that version 2.0 breaks backward compatibility with 4.6 platforms on the 'Find rules' action. Issue appears to be the call to function: CRM_Utils_System::getUrlPath() which doesn't exist on 4.6 versions.

File: CRM/Civirules/Form/Search/Rules.php
Line 22:

    $session = CRM_Core_Session::singleton();
    $url = CRM_Utils_System::getUrlPath();

To fix this, I added a condition on that part:

    // Set the user context
    $session = CRM_Core_Session::singleton();
    if ($this->_domainversion <= 4.6) {
      // Backwards compatible with 4.6 systems
      $url = CRM_Utils_System::currentPath();
    } else {
      $url = CRM_Utils_System::getUrlPath();  
    }

I'm also attaching a patch for that.
civirules-2.0-fix-compatibility-4.6.patch