BlockBasedTableConfig Filter policy support RocksJava

As proposed by yhchiang the filter can now be set in Java for
a BlockBasedTableConfig instance.
FilterTest
Merge pull request #330 from fyrz/setFilterPolicyForBBTConfig

BlockBasedTableConfig Filter policy support RocksJava
Fix build_tools/version.sh
Don't return (or dereference) dangling pointer
Merge pull request #333 from nbougalis/cleanups

Don't return (or dereference) dangling pointer
perf_context.get_from_output_files_time is set for MultiGet() and ReadOnly DB too.

Summary: perf_context.get_from_output_files_time is now only set writable DB's DB::Get(). Extend it to MultiGet() and read only DB.

Test Plan:
make all check
Fix perf_context_test and extend it to cover MultiGet(), as long as read-only DB. Run it and watch the results

Reviewers: ljin, yhchiang, igor

Reviewed By: igor

Subscribers: rven, leveldb

Differential Revision: https://reviews.facebook.net/D24207
Add number of records dropped in compaction summary

Summary:
Add two stats to compaction summary:
1. Total input records from previous level
2. Total number of records dropped after compaction

Test Plan: See outputs of printing when runnning locally

Reviewers: ljin, igor, MarkCallaghan

Reviewed By: MarkCallaghan

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D24411
Fix lint errors in java/rocksjni/options.cc

Summary:
Fix lint errors in java/rocksjni/options.cc

Test Plan:
make rocksdbjava
Fix a check in database shutdown or Column family drop during flush.

Summary:
Fix a check in database shutdown or Column family drop during flush.

Special thanks to Maurice Barnum who spots the problem :)

Test Plan: db_test

Reviewers: ljin, igor, sdong

Reviewed By: sdong

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D24273
Column family support in RocksJava

This commit includes the support for the following functionalities:
  - Single Get/Put operations
  - WriteBatch operations
  - Single iterator functionality
  - Open database with column families
  - Create column family
  - Drop column family
  - Properties of column families
  - Listing of column families

In addition there is an additional Java sample which can be build
using "make cfsample".

What is not supported currently using RocksJava:
  - Multi Iterator support
  - MultiGet

I decided to file a pull request w/o the missing two features to omit
some merging trouble. I would propose to hand them over to a later point
of time.
Quality improvements
- Replaced all NULL occurences in code with nullptr
- Removed iostream include
Fixed some lint problems
More lint problems fixed
Moved Testing code from Sample to Test.
Fixed line length in Test