Problem: does not support PLAIN authentication
Problem: does not support PLAIN authentication

Solution: expand configuration parsing to support this. Note that
security setting must come before any bind settings, as these are
executed in order. So:

    mlm_server
        echo = installing PLAIN security mechanism
        security
            mechanism = plain

        echo = binding mlm_client test service to 'ipc://@/malamute'
        bind
            endpoint = ipc://@/malamute

bkmit/zproto,vyskocilm/zproto,vyskocilm/zproto,bkmit/zproto,hintjens/zproto,c-rack/zproto,vyskocilm/zproto,hintjens/zproto,somdoron/zproto,somdoron/zproto,sappo/zproto,jemc/zproto,bkmit/zproto,hintjens/zproto,jdiez17/zproto,jdiez17/zproto,sappo/zproto,zeromq/zproto,bkmit/zproto,zeromq/zproto,c-rack/zproto,hintjens/zproto,jemc/zproto,hintjens/zproto,hintjens/zproto,asokoloski/zproto,sphaero/zproto,bkmit/zproto,somdoron/zproto,sphaero/zproto,sappo/zproto,jemc/zproto,sappo/zproto,asokoloski/zproto,asokoloski/zproto,somdoron/zproto,vyskocilm/zproto,jemc/zproto,jdiez17/zproto,sappo/zproto,sphaero/zproto,somdoron/zproto,zeromq/zproto,vyskocilm/zproto,asokoloski/zproto,zeromq/zproto,somdoron/zproto,jdiez17/zproto,zeromq/zproto,sappo/zproto,c-rack/zproto,jemc/zproto,sphaero/zproto,bkmit/zproto,vyskocilm/zproto,hintjens/zproto,jdiez17/zproto,c-rack/zproto,vyskocilm/zproto,sappo/zproto,sphaero/zproto,c-rack/zproto,zeromq/zproto,asokoloski/zproto,asokoloski/zproto,c-rack/zproto,zeromq/zproto,bkmit/zproto,sphaero/zproto,jemc/zproto,jdiez17/zproto,asokoloski/zproto,somdoron/zproto,c-rack/zproto,jdiez17/zproto,jemc/zproto