gmi.c:
Remove BINDTODEVICE socket option and replace with MULTICAST_IF
to be more portable and require less root privs.

BKrev: 410583008afZgkQ66_jDep-8pFf_nw


git-svn-id: http://svn.fedorahosted.org/svn/corosync/trunk@120 fd59a12c-fef9-0310-b244-a6a79926bd2f