Overhaul of configuration parsing

* Created basic structure for new configuration loading
* Wrote configuration parsing and loading for common configuration and listeners configuration
Numerous changes, in the process of refactoring of the architecture
Removed old mediators and config parsing code, added config loading
Started rewrite of communicators/listeners
Removed old config structures and changed common types
Multiple changes: logging, discovery, configuration

* Added docs to version control
* Wrote logging subsystem
* Updated discovery configuration
* Wrote basic discoverer
* Wrote node implementation