multimaster_fkie:
* discovering:
  - changes in discovery interface to reduce the load on network
* synchronization:
  - added function for congestion avoidance, which reduce the
    state requests
  - synchronzation interface files added
  - sync topics on demand option added
* node manager:
  - the most of actions (start, stop, open io, ...) are now
    executed in threads to avoid blocking
  - added handling for sync interface
  - starts more then one default_cfg on a host
* a lot of small changes and fixes