refactor:delete unused methods
add safecopy mode
Merge branch 'master' of git@github.com:roma/roma into safe_copy
add test for safecopy
add command of strage status
add method for cachecleaning
add command process for safecopy
Add status log
Add check and open cache in opendb
Add storage backup command
add test code for the safecopy
modify default value(nil -> false) & modify ongoing command bug
Merge pull request #16 from hiroaki-iwase/Latency

modify default value(nil -> false) & modify ongoing command bug
fix : warning of class variable access from toplevel
add : case of unable to @expire_time
bugfix : for the RubyHashStorageTest
add safecopy test for rbalse, join, recove in multi server
modify check script
modify script2
change test name
add sleep for test without snapshot process (basically comment out)