changed import class using wildcard to import statements without wildcard.
rename StateManager to OLDStateManager for re-implementation it and keeps compatibility of it.
create empty classes. this commit should be amend.
test commit of implementation of state manager module.
implemented notify mechanism of state change
fix spell miss
changed a constructor signature
implementing write process with state transitions.
completion normal storage with state management
Merge branch 'implement_state_manager' into base_copy

Conflicts:
	src/jp/ac/titech/cs/de/ykstorage/storage/datadisk/NormalDataDiskManager.java
changed argument type of StateManager constructor. and its test code.
deprecated old state manager for maid.
Rename maid storage manager modules to OLDMAIDxxx due to replace with new modules.
Rename maid data disk manager modules to OLDMAIDxxx due to replace with new modules.
pull up instantiation of a field of storage manager.
Create classes related to MAID storage module.
implemented basic process of MAID storage manager and its factory
starting implementation MAID data disk manager
implemented MAID modules and its test code.
add idleness watchdog timer. And fixed a bug about buffer write