change code about comparing time
add pages for overload monitor page, modify default interval from 1 day to 8 hours
remove invalid code
prevent add duplicate domains to the product line
fix test error
add tag module
Merge branch 'master' of https://github.com/dianping/cat
Merge pull request #520 from leonindy/master

add tag module, add constraint that domain belongs to only one productline, add js for overload page