Metacat

experiment with lifecycle pause/resume. hopefully it prevents our node from taking ownership of any keys before we are sure we have them all.

increase logging and add back in the call to saveLocally() in case the SM object has already been loaded into the shared map but before this node came back online.

no need to call saveLocally explicitly since loading from the shared store triggers that behavior locally because of the configured listeners.
use an iterator over the shared identifiers in case this set is constantly changing.

make only one DB call to look up local pids - no need to do a pstmt for every single shared pid.

on init (start up) launch a synchronization thread that ensures all shared identifier entries have a corresponding local System Metadata entry.

fix NPE (logMetacat object was not initialized) that was occurring during store()

share the same dbConnection when inserting and then updating SystemMetadata objects in the backing store.
any errors encountered during the update will rollback the entire transaction and the SM record will not exist, even in part.

Do not loadAllKeys() for SystemMetadataMap when Metacat first starts up. hzIdentifiers will be populated with a simple SQL statement rather than the serial loading of every single SystemMetadata object. It will remain in synch using the usual entryXXX() methods as before....

only generate system metadata for original objects.
https://redmine.dataone.org/issues/2721

add comment about returning early when no system metadata can be found.
removed extraneous check on the content type of the SM -- was unused.
formatted indenting