added tooltip help page URL comment
prune scripts are causing <defunct> shell processes to accumulate so dont use them
started looking at being able to highlight selected filenames in the filename list in the test page
refactoring (1) remove unneeded <input radio>s for test-page and diff-page filenames, in particular this avoids the radio bullets being flashed on/off when you < > navigate (2) added :highlight_filenames option to language manifest