Listing of changes

- JavaDoc readability of RocksObject JavaDoc
- JavaDoc improvements BlockBasedTableConfig, GenericRateLimiterConfig, RocksDB
- JavaDoc improvements MemTableConfig
- JavaDoc improvements RocksObject
- JavaDoc improvements GenericRateLimiterConfig
- JavaDoc improvements ReadOptions
- JavaDoc improvements RateLimiterConfig
- JavaDoc improvements RestoreOptions
- JavaDoc improvements RestoreBackupableDB
- JavaDoc improvements BlockBasedTableConfig
- JavaDoc improvements Options
- JavaDoc improvements BackupableDB and BackupableDBOptions
Fixed Findbugs issues

- BackupableDB missing call to super.finalize(major)
- WriteBatchTest inefficient String usage(minor)
- RocksDB local dead variable store(medium)
Lint changes
Merge pull request #331 from fyrz/findbug_issues

Fixed Findbugs issues in RocksJava
Merge pull request #334 from fyrz/JavaDoc-Cleanup

JavaDoc fixes & enhancements RocksJava
OpenReadOnly support in RocksJava

Changes:
- new Method: RocksDB openReadOnly(String path)
- new Method: RocksDB openReadOnly(Options options, String path)

Missing:
- Column family support is blocked by #319