Built-in comparator(s) in RocksJava

Extended Built-in comparators with ReverseBytewiseComparator.

Reverse key handling is under certain conditions essential. E.g. while
using timestamp versioned data.

As native-comparators were not available using JAVA-API. Both built-in comparators
were exposed via JNI to be set upon database creation time.
Changed name of ReverseBytewiseComparator based on review comment
handle kDelete type in cuckoo builder

Summary:
when I changed std::vector<std::string, std::string> to std::string to
store key/value pairs in builder, I missed the handling for kDeletion
type. As a result, value_size_ can be wrong if the first add key is for
deletion.
The is captured by ./cuckoo_table_db_test

Test Plan:
./cuckoo_table_db_test
./cuckoo_table_reader_test
./cuckoo_table_builder_test

Reviewers: sdong, yhchiang, igor

Reviewed By: igor

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D24045
Merge pull request #316 from fyrz/ReverseBytewiseComparator

Built-in comparator(s) in RocksJava
Add AUTHORS file. Fix #203
use GetContext to replace callback function pointer

Summary:
Intead of passing callback function pointer and its arg on Table::Get()
interface, passing GetContext. This makes the interface cleaner and
possible better perf. Also adding a fast pass for SaveValue()

Test Plan: make all check

Reviewers: igor, yhchiang, sdong

Reviewed By: sdong

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D24057
CompactedDB: log using the correct info_log

Summary:
info_log from supplied Options can be nullptr. Using the one from
db_impl. Also call flush after that since no more loggging will happen
and LOG can contain partial output

Test Plan: verified with db_bench

Reviewers: igor, yhchiang, sdong

Reviewed By: sdong

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D24183
Make test use a compatible type in the size checks.
Merge pull request #321 from eonnen/master

Make test use a compatible type in the size checks.
Fix arc lint (should fix #238)

Summary: See https://secure.phabricator.com/D9114

Test Plan: arc lint

Reviewers: yhchiang

Reviewed By: yhchiang

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D24195
Ignore IntelliJ idea project files and ignore java/out folder
Feature - Implement Java API for Comparator and Slice. Allows use of
either byte[] or DirectByteBuffer for accessing underlying data.
Add locking to comparator jni callback methods which must be thread-safe
Fix to memory dealocation when creating a slice from a byte buffer
Fix code style problems identified by lint
Tests for ComparatorOptions, Comparator and DirectComparator, and by
proxy we also exercise Slice and DirectSlice