LevelDB Storage Engine: re-commit in git against webscale
Re-commit in Git: Port to RocksDB. Let LevelDB engine be optional.
Also added HTON_SUPPORTS_EXTENDED_KEYS to both engines.
Re-commit in git: fake support for UNIQUE indexes. They can be created for RocksDB but won't be enforced.
re-commit in git:Fix rocksdb to build when bz2 library is present.
Make RocksDB SE compile in webscale.
Re-commit in git: Post-fixes after UNIQUE index support was
enabled without uniqueness enforcement.
- Fix compile warning
- Fix the rocksdb.test/result
Re-commit in git:  Explicit insert into an auto-inc column is not noticed by RocksDB

Basic fix: don't forget to update the table-wide auto-increment value.
Update rocksdb.result after moving from MySQL to webscalesql.
Fix compile warning
Add generated files .gitignore
Fix Issue #1: AUTO_INCREMENT value doesn't survive server shutdown

Use ha_rocksdb::open() should check table->found_next_number_field,
not table->next_number_field (like InnoDB does)
Fix Issue #3: SHOW TABLE STATUS shows Auto_increment=0
Fix compiler warnings
Add passing tests in mysql-test/suite/rocksdb (based on mysql-test/suite/leveldb)
More tests in suite/rocksdb: tbl_opt_ai, update_with_keys.
Add another testcase: suite/rocksdb/update_ignore.test
Fix Issue #4: Crash when using pseudo-unique keys
Fix Issue #4, part#2: make other members of class RDBSE_KEYDEF aware that unique keys do not have index extensions defined.

Also add suite/rocksdb/type_int_indexes.test
Add more tests to mysql-test/suite/rocksdb/
Add remaining tests to mysql-test/suite/rocksdb. This fixes Issue #1

Two testcases are empty because RocksDB-SE doesn't support the feature:
-autoincrement.test
-autoinc_secondary.test