0.9.4 release

Big features

1. Add transaction programming mode
2. Rewrite netty code
   • use share boss/worker thread pool
   • async send batch tuples
   • single thread to do reconnect job
   • receive batch tuples
3. Add metrics and statics
4. Merge Alimama storm branch into this version, submit jar with -conf, -D, -lib

Enhancement

1. add setting when supervisor has been shutdown, worker will shutdown automatically
2. add LocalFristGrouping api
3. enable cgroup for normal user

Bug fix:

1. Setting buffer size when upload jar
2. Add lock between ZK watch and timer thread when refresh connection
3. Enable nimbus monitor thread only when topology is running in cluster mode
4. Fix exception when failed to read old assignment of ZK
5. classloader fix when both parent and current classloader load the same class
6. Fix log view null pointer exception