change hadoop version
modify the npe
merge code
fix monitor api bug
Merge pull request #680 from jialinsun/master

fix bug
modify the creator
modify the topogygraph build
Merge pull request #681 from youyong205/master

fix bug
add isMonitor attribute to DisplayPolicy model
change serval methods in DisplayPolicyManager
refactor HeartbeatAlert
refactor Heartbeat history part
Merge branch 'master' of github.com:dianping/cat

Conflicts:

cat-home/src/main/java/com/dianping/cat/report/page/heartbeat/HistoryGra
phs.java
Merge pull request #682 from leonindy/master

refactor heartbeat history part
rename monitor and delta attributes in DisplayPolicy
add extension metrics when setting heartbeat alert rule
rename monitor attribute of DisplayPolicy
refactor heartbeat alert
refactor alert module: extract RuleConfigManager to a abstract method
Merge branch 'master' of github.com:dianping/cat