Merge hierarchy store into Tachyon - thrift change
Merge hierarchy store into Tachyon - non-thrift change
refactor promote block code, adding comments and format
remove DropAfterPromote and configuration change
clean code and some bug fix
try to get block information from worker when information from master is outdated
fix test cases for TachyonFS
heartbeat simplify thrift change
heartbeat simplify non-thrift change test OK
fix NullPointerException in TachyonFile
refact lockBlock and unlockBlock delete getBlockFileInfo - thrift change
refact lockBlock and unlockBlock delete getBlockFileInfo - non-thrift change
modification on BlockHandlerLocalTest and WorkerStorageTest
Refactor and code clean
make worker reclaim space from user to make sure all space be reclaimed when user is removed
modify according to comments
move cached info from TachyonFS to WorkerClient
initialize workerDir FS during initialization of WorkerClient
remove StorageDIrId in remote read and lock/unlock block - thrift change
remove StorageDIrId in remote read and lock/unlock block - non-thrift change