Download Runtime task wizard has opportunity to block UI

Several pieces of code call various methods such as RuntimeCoreActivator.getDefault().getDownloadRuntimeArray();

These methods do not use progress monitor, and, if the list of DownloadRuntimes has not successfully completed once before, will be a long-running task.Since they are called directly from the UI, this has the potential to block the UI with no feedback to the user and no way to cancel.