Log Message:
Update ruby-net-http-persistent to 2.9.

=== 2.9 / 2013-07-24

* Minor enhancement
  * Added max_requests to avoid ECONNRESET for a server that allows a limited
    number of requests on a connection.  Pull request #42 by James Tucker.
  * Request failures are now raised with the backtrace of the original
    exception.  This gives better insight into the reason for the failure.
    See #41 by Andrew Cholakian.
  * OpenSSL is no longer required.  If OpenSSL is not available an exception
    will be raised when attempting to access HTTPS resources.  Feature request
    by André Arko

* Bug fixes
  * Explain the proper way of sending parameters depending upon the request
    method.  Issue #35 by André Arko.
  * Handle Errno::ETIMEDOUT by retrying the request.  Issue #36 by André Arko.
  * Requests retried by ruby 2.x are no longer retried by net-http-persistent.
  * Finish the connection if an otherwise unhandled exception happens during a
    request.  Bug #46 by Mark Oude Veldhuis.
  * detect_idle_timeout now assumes a StandardError indicates the idle timeout
    has been found.  Bug #43 by James Tucker.