submission sidebar details display

This will close #1021 if you are in favor of the following changes and decide to merge it.  Take it for a spin, I think you'll like it.
- made DRYer by reusing a contents details partial (moved the content details from the top to the side-- the approval buttons are still at the top
- made more consistent with the rest of the app by removed the touch unfriendly "hover over content to display Edit Content link" feature (which took you to the show instead of the edit) and added an "Edit Content" button in the header (just like our other pages)
- added duration to the content details sidebar
- removed the pencil/edit duration feature (which was, I believe, left over from a time when that was all you could edit-- so instead of having two ways to edit [the pencil or clicking on the hover text mentioned above] now there is only one -- the edit button