also enforce allow_mult at write-time in vnode
also enforce allow_mult at write-time in vnode

yangchengjian/riak,basho/riak_search,wwezhuimeng/riak_search,basho/riak_search,glickbot/riak,planobe/riak,xuejianhai/riak,wwezhuimeng/riak_search,planobe/riak,GabrielNicolasAvellaneda/riak,authbox-lib/riak,DavidAlphaFox/riak,basho/riak,xuejianhai/riak_search,elkingtonmcb/riak,amyvmiwei/riak,xuejianhai/riak_search,laurenrother/riak,biddyweb/riak