Adding reference to older MDP/? in README
Adding reference to older MDP/? in README

I've tagged the previous versions of those implementations. This fixes
issue #33.

ajanicij/majordomo,eburkitt/majordomo,eburkitt/majordomo,eburkitt/majordomo,zeromq/majordomo,ajanicij/majordomo,eburkitt/majordomo,zeromq/majordomo,ajanicij/majordomo,eburkitt/majordomo,ajanicij/majordomo,zeromq/majordomo,zeromq/majordomo,eburkitt/majordomo,zeromq/majordomo,zeromq/majordomo,ajanicij/majordomo,ajanicij/majordomo,ajanicij/majordomo