JBIDE-17541 - Replace use of Slf4j with Eclipse Logger in JAX-RS UI tests
JBIDE-17540 - Replace use of Slf4j with Eclipse Logger in JAX-RS core tests
JBIDE-17543 - Investigate JUnit test duration

Not major improvement, despite a few changes

Also fixed JBIDE-17551 (renamed ui.test 'Logger' to 'TestLogger')