1.18.3

release:1.18.3

   1. add filterPolicy
   2. update snappy
   3. support arm64
   4. remove 32bit,remove win

1.18.2

release 1.18.2

 1. update leveldb-api

1.23.2

1. writeBatch add clear,approximateSize,append
2. add java doc

1.23.1

change prev():

1. prev(): return current and then prev.
2. hasPrev(): is equal to Valid(),hasNext().
3. peekPrev() is equal to peekNext(), peekPrev() and peekNext() is marked as Deprecated, use key(),value().

1.23

update leveldb-api.