Removes merge conflict notes from prism css file.
Corrects (I think) the view for prism visualization.

There have been some contradictory commits since @bwalsh
committed at 6e437596c8c3662a693888f93f4ead2bb9885981. This commit reverts the
code back to that point, but adds the important semicolons to the javascript
code near the top, which @waynegraham added in 502fac2bba286be82352b0175c07297a665f9386.
Moves Prism CSS to an include.

Includes it in main application.css. Leaves it outside a particular media
query for now, since we may want the highlights printed out.