MultiGet column family extension.
Java6 compatibility
Resolved warnings reported by IDEA
Renamed openColumnFamilies to open method in native bindings
OpenReadOnly support in RocksJava

Changes:
 - new Method: RocksDB openReadOnly(String path)
 - new Method: RocksDB openReadOnly(Options options, String path)
JavaDoc enhancements in RocksDB.open methods
RocksDB ReadOnly support with column families

- openReadOnly extension for column families
- Makefile cleans up now tmp folders properly
- ReadOnlyTest
Making things lint clean
Improved test output, Fixed StatisticsCollectorTest
MultiIterator support implemented