This adds a stub implementation for the compaction_manager API.
The methods return the right types but with a stub value.
After this patch the following url will be available:
/compaction_manager/compactions
/compaction_manager/compaction_summary
/compaction_manager/force_user_defined_compaction
/compaction_manager/stop_compaction
Signed-off-by: Amnon Heiman <amnon@cloudius-systems.com>
