add interface of buffermanager and buffermanager implementation for RAPoSDA.
add debug flag to Parameter.
add RAPoSDABufferManager. and change RAPoSDAStorageManager to use the buffer manager.

for bfa_tik_06
change the storage manager interface and the member access identifier from protected to public.

for bfa_tik_06
create EnergyEfficientBufferManager and its factory.

for bfa_tik_06
implemented energy efficient buffer manager. but need debug.

for bfa_tik_06
several changed.
bug fix bug002.
Merge branch 'bug002' into bfa_tik06
buf fixed. and implemented bfa_tik_06
add buffer size command line argument
change log method level from debug to trace to avoid outout the unnecessary logs
addition the time of each disk state to the energy log.
change the log level from trace to info.
add timestamp information to the exception message.
add logginig code for debug of buffer flush behaviour.
add arrival time debug log
change coefficient unit from joule to watt in calculus the energy efficiency of disk subset.
change the value of energy efficiency coefficient
change the coefficient value.