0.2.1-beta 版本

发布日期: 2015-01-08

pull request 26: Use binaries for topic paths and fix wildcard topics

emqtt_pubsub.erl: fix wildcard topic match bug caused by binary topic in 0.2.0

Makefile: deps -> get-deps

rebar.config: fix mochiweb git url

tag emqtt release accoding to [Semantic Versioning](http://semver.org/)

max clientId length is 1024 now.