finish alert monitor page backend job
for stage current work
add select type feature
rename some vars to make logic more clean
Merge branch 'master' of https://github.com/dianping/cat
change AlertType to enum, modify sendRecoveryMail method
recover CatHomeModule
change send recover mail logic
Merge pull request #459 from leonindy/master

add alert-monitor page, change logic of sending alert-recover mail