add backend of high load sql module
add new table highload_sql
fix serval bugs in HighLoadSqlUpdater
add highload page
refactor highroad module, which makes expand easier
add HighloadSqlUpdater
refact frontend modules of highload module
Merge branch 'master' of https://github.com/dianping/cat
add compare feature for fronted of highload module
add compare feature for backend of highload module
Merge pull request #592 from leonindy/master

add highload module