[bh] Close all pre-benchhub issues #60
[bh] Close all pre-benchhub issues #60

- simple web ui will be kept
- benchmark will be moved back to xephon-b with more workloads and more
metrics (even traces)
- collector will be moved to either benchboard or benchhub's lib
directory and becomes a standalone library eventually
- local disk and cassandra store might need some rewrite, could just
focus on write due to time budget

xephonhq/xephon-k,xephonhq/xephon-k,xephonhq/xephon-k,xephonhq/xephon-k,xephonhq/xephon-k,xephonhq/xephon-k