update CHANGELOG for the 1.0 release
update CHANGELOG for the 1.0 release

rickypai/zookeeper,rickypai/zookeeper,songling88/zookeeper,zk-ruby/zookeeper,songling88/zookeeper,zk-ruby/zookeeper,rickypai/zookeeper,songling88/zookeeper,rickypai/zookeeper,songling88/zookeeper,zk-ruby/zookeeper