Test fixes + OLocalPaginatedCluster + File lock changes

This pull request contains 3 changes:

1) Test fixes
2) Adding missing setSofltyClosed call for the clusterStateHolder in OLocalPaginatedCluster. This fix prevent waring "Cluster * was not softly closed" during startup after proper shutdown.
3) Replace exclusive lock with shared for database files. Due to this changes other programs will still not be able to change database files, but will be able to read them. This will make possible to perform backups tasks while database is running.