fixed the dump_extents non stop bug. It is actually in filefrag()
create tmpfs mountpoint if it does not exist
remove verbose
updated producer.py. added ADD OPEREATION function so that we can add operations to the workload.
use os.path.join() to join directories and files
have been using walkman-lonely.py for a while. it:
1. has the nice wapper to setup environment and record system status.
2. calls fsbench to do some thing the workload player cannot do - change cpu