LTDB release v0.0.7

modify KNNSCAN function to support BatchKNNSCAN as well

LTDB release v0.0.6

Modify type of METAKEYSWITHFILTER command

LTDB release v0.0.5

modify LTDB command function: KNNSCAN

LTDB release v0.0.4

add LTDB command: KNNSCAN

LTDB release v0.0.3

add ClusterClient's methods: GetMasterNodesCount() and GetSlaveNodesCount()

LTDB release v0.0.2

add LTDB commands: METAKEYS, METAKEYSWITHFILTER, GETMETA, GETROWCOUNT