Scheduled tasks admin: usability enhancements

There is some Behat coverage. Manual testing: Log in as admin. Navigate to Site administration > Server > System Paths Set the "Path to PHP CLI" (pathtophp) to your path to PHP Note: On *nix-like systems, you can find this out by typing the following into the terminal: which php Go to Administration > Server > Tasks > Scheduled tasks Verify that for each Component (e.g. Forum), the internal name (mod_forum) is also shown. Verify that you can see which components are disabled. Scroll down, and click edit on a task in the middle of the table. Change some numbers, and click Save changes. Verify that the page scrolls to the task you edited, and that table row is highlighted. Click edit on a different task. Click Cancel. Verify that the page scrolls to the task you edited (even though you did not change anything) and that table row is highlighted. Verify that on the row you edited before, the numbers you changed are now highlighted, and the default is shown. Note the fact that you cannot see the highlighted cells in the last-edited row is a Bootstrap bug ( https://github.com/twbs/bootstrap/issues/29290 ). There is nothing we can do about this, but since this is an admin-only UI I think we can live with it. Click Run now on some task. Click Cancel. Verify the row where you clicked the Run now link is now highlighted. Click Run now on some task. Click Run now. Click Back to scheduled tasks. Verify the row for the task you jsut ran is now highlighted. If you can find a row in the table where 'Fail delay' is different from zero, click the Clear link. (If you can't find this, just stop testing now. This next bit is mostly tested be Behat anyway.) Click Cancel. Verify the row where you clicked the Clear link is now highlighted. Click the Clear link again. Click Clear. Verify the row where you clicked the Clear link is now highlighted.