Misc features

This branch moves the thCloneJobs properties, lastJobElSelected and lastJobObjSelected, to properties on ThResultSetModel.repositories[repoName]. This allows the job selection styles to persist across repo selections and job updates and be correctly removed with subsequent job selections. It also makes it easy to expose which HTML element is associated with the selected job. This might come in handy for plugins in the future. Also added the middle mouse button click to automatically open the log file in a new window.