Show top & fav databases and "other" databases in separate lists

[kenirwin]

• LibAppsDataFilter adds a "isTopForSubject" (true/false) field to each database in each cache/subjects/ file
• UserLibGuidesData.getSubjectFiles() sorts database for each subject into two arrays: "aboveFold" (includes user favorites and "isTopForSubject: true") and "belowFold" (everything else); this happens in the /json data and the data handed off to the view renderer
• views/subject-info.ejs handles rendering of "aboveFold" and "belowFold" arrays. If there are any "aboveFold" databases, they are all displayed in one list in the top accordion; any "belowFold" databases are folded up in an "Other Databases" accordion. If there are no top/favorite databases, then there are no accordions -- just display the list of all databases for the subject.

Still need to decided if this is the best way to render the data.

This PR also updates sass and bootstrap files in the dev environment. If we decide not to merge this PR, we'll still want to include those updates.