2883: Added radio buttons to filter tasks by success/failure.
some refactoring and added detection of task success or failure
Merge remote-tracking branch 'origin/origin-2883-job-log-viewer' into 2883-job-log-viewer
2883: Fixes secondary key sort bug.  Adds filtering on successful/failed tasks.
2883: Fix pattern for discovering success/failure of tasks.
2883: Added overview, node column and sort by node, style tweaks.
2883: Added node slots as its own column.
2883: Distinguish between complete/incomplete and success/failure.
2883: Added big red "show failed tasks" button.
2883: Added pagination for large logs.
2883: Improved pagination control a bit, added search.
Merge branch 'master' into origin-2883-job-log-viewer
2883: Use smart scrolling so keep the sorting and filtering selections on the
page when scrolling the output.
Add error handling when log collection is not found. refs #3027.
Merge branch '2883-job-log-viewer' of git.curoverse.com:arvados into origin-2883-job-log-viewer

Conflicts:
	apps/workbench/app/views/jobs/_show_log.html.erb
2883: Fixed variable being used before it was declared, and fixed assignment of
ids to rows.
2883: Changed "task-output" category to "task-print" and "output" to
"diagnostic" in the UI text based on AWZ feedback.
2883: Fixed select all/select none messing with the "show task" radio buttons.
Merge branch 'origin-2883-job-log-viewer' closes #2883 refs #3027