gmi.c:
Flush all multicast messages by delivering them before
processing the token. This ensures that the mcast fd
doesn't buffer too many old messages and avoids an assert.

BKrev: 412fd3cesE7M-pXl9OZs1X2CyK7Y4A


git-svn-id: http://svn.fedorahosted.org/svn/corosync/trunk@209 fd59a12c-fef9-0310-b244-a6a79926bd2f