Add support for Column Families in a runtime safe way.
Add unittests to test functionality
Insure all unittests are passing.
Cleaned up unittests to not use a fixed directory in tmp, but use tempfile

Merge options source_compaction_factor, max_grandparent_overlap_bytes and expanded_compaction_factor into max_compaction_bytes

See https://github.com/facebook/rocksdb/wiki/Prefix-Seek-API-Changes