Changes to apr_pollset_method_e enum value of APR_POLLSET_POLL and
APR_POLLSET_AIO_MSGQ.  Restore APR_POLLSET_POLL to its pre-r1308910 
(April 2012) value, and move APR_POLLSET_AIO_MSGQ ahead. This restores
ABI compat with released branches. 



git-svn-id: https://svn.apache.org/repos/asf/apr/apr/trunk@1534266 13f79535-47bb-0310-9956-ffa450edef68