LDVSpec usability improvements

1. Updated successor/predecessor column labels

Tested layout on minimum of 1280x1024, seemed fine.

2. Added autoselection of item in some dropdowns on workspec/group form if that item is the only value

Since it involves frontend (JavaScript) logic, integration robot tests were added.

3. Added visual indication if task does not contain any files

Badge color is changed to a beautiful orange color when task doesk not contain files. Tooltip is also different. An asterisk is appended to the submission status, mostly for integration testing purposes, but I think that's fine.

Since it involves frontend (JavaScript) logic, integration robot tests were added.

4. Add links to embedded user guide

I've tried to make it look as pretty as possible with the least amount of time. The header text was changed from primary (e.g., dark blue'ish) to black, to contract with the user guide link. This way, it looks similar to tooltips and recognizable. I extracted the user guide link html to a partial template for easier re-use and to prevent copy/pasting. Not in the story, but I added the same links to the user guide on the craete/add group forms as well.