Various enhancements to build.xml * Use https for pentaho repository location * Add some more targets to "jenkins" target * Add download of maven-ant-task to make target "maven-install" work without manual installation into the ant-home directory * Update JaCoCo to 0.8.3 and asm to 7.0 This should now also work with JDK 13 pre-builds, so enable coverage in the JDK 13 CI builds again