[mysql5.6.4] enable MRN_PLUGIN_HAVE_FLAGS.
[mysql5.6.4] enable MRN_PLUGIN_HAVE_FLAGS.

yoku0825/mroonga,naoa/mroonga,naoa/mroonga,naoa/mroonga,yoku0825/mroonga,naoa/mroonga,mroonga/mroonga,mroonga/mroonga,naoa/mroonga,mroonga/mroonga,yoku0825/mroonga,yoku0825/mroonga,yoku0825/mroonga,mroonga/mroonga,naoa/mroonga,yoku0825/mroonga