--- /dev/null
+1. Use json file instead of dbm to save state on disk. It is small
+ enough to overwrite it completely each time it changes and no
+ need to support cocurrent access
+2. Check mtime of configuration file and reread it if it changed.
+ Requires some refactoring
+ (log error and continue to use old loaded configuration if new file
+ contain errors. Store new timestamp to watch for further
+ modifications)
+