runner.home: optional path to runner home (root directory with sub-directories bin, lib and conf)
runner.settings: optional path to runner global settings, usually ${runner.home}/conf/sonar-runner.properties.
This property is used only if ${runner.home} is not defined
project.home: path to project root directory. If not set, then it's supposed to be the directory where the runner is executed
project.settings: optional path to project settings. Default value is ${project.home}/sonar-project.properties.