Added
* logc - logging support
* connected ZMQ peers monitoring
* check - unit tests
* cppcheck - linting
* lcov - code coverage
* valgrind
* Gitlab CI
* pkg-config and version scripts for device token library
* more fields in configuration file - it can hold the whole config now
* manual overall tests

Changed
* split server CLI option to server and port options
* CLI options - names, arguments and their descriptions updated