Added writable check for PIPE_DIR
Added writable check for PIPE_DIR

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