fix RocksDB java build

Summary: as title

Test Plan: make rocksdbjava

Reviewers: sdong, yhchiang, igor

Reviewed By: igor

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D23193
[unit test] CompactRange should fail if we don't have space

Summary:
See t5106397.

Also, few more changes:
1. in unit tests, the assumption is that writes will be dropped when there is no space left on device. I changed the wording around it.
2. InvalidArgument() errors are only when user-provided arguments are invalid. When the file is corrupted, we need to return Status::Corruption

Test Plan: make check

Reviewers: sdong, ljin

Reviewed By: ljin

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D23145
Push model for flushing memtables

Summary:
When memtable is full it calls the registered callback. That callback then registers column family as needing the flush. Every write checks if there are some column families that need to be flushed. This completely eliminates the need for MakeRoomForWrite() function and simplifies our Write code-path.

There is some complexity with the concurrency when the column family is dropped. I made it a bit less complex by dropping the column family from the write thread in https://reviews.facebook.net/D22965. Let me know if you want to discuss this.

Test Plan: make check works. I'll also run db_stress with creating and dropping column families for a while.

Reviewers: yhchiang, sdong, ljin

Reviewed By: ljin

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D23067