Review Board 1.7.22

implement a hedwig console to use/intract with/admin hedwig system.

Review Request #2570 - Created Oct. 26, 2011 and updated

Sijie Guo
using zookeeper client to read metadata, use hedwig client to interact with hedwig, use bookkeeper client to openLedgerNoRecovery to read messages to implement a hedwig console

Review request changed
Updated (Feb. 2, 2012, 12:48 p.m.)
attach a new patch based on trunk. in this patch, I did some cleanup to move all the meta-related operations such as getTopics, show topic info into a admin class.