Implement cong.logginglogger.ifExists=OVERWRITE | MERGE
Class Javadoc
Class Javadoc
MIGR-104  Support action depending on each other
MIGR-104  Support action depending on each other  - Implement ActionDependencySorter.
Make checkState() throw RuntimeException as it only appears during development.
Fix backup mechanism
MIGR-104; make dep sorter deterministic.
Fix backup mechanism
Improve checkState()
Fix backup mechanism
Remove sorting by hashCode()  - All right that was not a good idea - it breaks those from Migrators which don't set dependency yet...
Sort the actions according to their dependency on each other.
Add few debug lines.
@Override