Activates Spring Boot Actuator with a basic config;
Introduces Spring Boot Actuator metrics;
Reconfigures thread pool sizes for websocket messaging;
Adds Actuator PublicMetrics aggregator and ThreadPoolMetrics;
Enhances client side websocket connection creation;  Scales up queue size for WS inbound channel.
Merge branch 'master' of https://github.com/datenstrudel/bulbs-core into master_org
Moves all tests into surefire plugin, separated by different executions bound to phases 'test' and 'integration-test'