Update to latest JaCoCo 0.6.3, fix easyMock dependency, add SLF4J implementation during testing to avoid output in maven test-runs
Configure eclipse plugin to exclude outdated asm 2.x versions pulled in by Jenkins dependency on 1.426 to allow unit tests which use JaCoCo to be run in Eclipse, they require asm 4.x
Loosen check in unit test somewhat to allow it to run in CI as there the JaCoCo.exec file might be empty