add AppMaster fault tolerance
revert status manager
add Post and Get application data
fix ClockService bug
refactor the Log format
Merge remote-tracking branch 'upstream/master'
revert ClockService change
fix ClockService
change packages and add storage
refactor code
minor fix
refacor interface
refine AppDataStore interface
add serde and factory to key value store
extract AppDataStore implementation from AppMaster
fix bugs in configuration
delete StorageManagerFactory
remove AppDataStore Update verification
Merge pull request #95 from huafengw/master

add AppMaster fault tolerance
close checkpoint manager when closing StorageManager