Merge pull request #27 from xiatao123/master

fix timeline issue and 10min interval
Profile the time spend on fetch stories. Optimize the call from 6000ms to 1300ms.
query user stories :  625 ms
find by user own top_stories!
map ids to BSON objectID :  676 ms
chop first num stories :  676 ms
query top stories :  1361 ms
modify each story :  1370 ms
sort story by score :  1370 ms
Total FindAll time spent :  1377 ms
Enhance the header bar UI. First, cache unnecessary ajax call to server and refresh. Second. make it change style according to different situation.
Make a few small UI improvements.
Add Skeleton for Admin story page.
Add hourly and daily KPI calculation.
Fixed security issue and header tag rendering issue.
added factor discoun for different interested interval