[Java] Add Java support for cache sharding.

Summary:
Add setCacheNumShardBits() and cacheNumShardBits() to Options.  This allows
developers to control the number of shards for the block cache.

Test Plan:
make rocksdbjava
cd java
make db_bench
./jdb_bench.sh --cache_size=1048576 --cache_numshardbits=6

Reviewers: sdong, ljin, ankgup87

Reviewed By: ankgup87

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D19347
Fixing memory leaks in cuckoo_table_builder_test

Summary: Fixes some memory leaks in cuckoo_builder_test.cc. This also fixed broken valgrind_check tests

Test Plan:
make valgrind_check
./cuckoo_builder_test
Currently running make check all. I shall update once it is done.

Reviewers: ljin, sdong, yhchiang, igor

Reviewed By: igor

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D20385
Fix signed-unsigned compare error
Merge