Adapt to partition split

[hycdong]

Functions:

• According to issue fill in partition_hash in thrift header #39 , we fill correct partition_hash value in thrift_header
• Add need_check_hash filed in get_scanner_request
  • hash_scan scanner: need_check_hash = false
  • unordered_scan scanner: need_check_hash = true
  • After partition split, parent will hold data belonging to child, and child will also have data belonging to parent. As a result, we have to check hash while executing unordered_scan to remove duplicated data. However, we don't need to check hash while hash_scan. Hash_scan will scan only one partition, it won't have duplicated data.

Tests:
We run java client unit test succeed on different onebox with different server version:

• client -> old server(version 1.11.3)
• client -> new server(supporting partition split)