Fixes #2588: "My progress" and "Help" links should be hidden for WCH.
Puts body of PDFjs viewer.html into pdf handlebars template.
Loads pdfjs files and sets defaults in topics.html.
Adds interim changes to make pdfjs initialize from within Backbone.
Adds basic styles for pdf container.
Modifies viewer.css and viewer.js to prevent unwanted automagic.
Fixes #2586: moved related content to below the content area.
Reenables points tracking for pdf views.
Prevents pdfjs setting document title to pdf URL.
Fixes #2585: Description is unreadable on PDF content view page
More robustly check if DOMElement is undefined when unbinding listenToDOM.
Prevent pdfjs toolbar from popping over modals and sidebar.
Fixes #2587: Moves download button to right-hand side of content panel.
Merge pull request #2610 from jamalex/2588

Several fixes for content view wrapper
Merge pull request #2606 from jamalex/2588

Fixes #2588: "My progress" and "Help" links should be hidden for WCH.
Merge branch 'develop' of github.com:learningequality/ka-lite into develop
Merge pull request #2609 from rtibbles/pdfjs_robust

Run PDFJS directly, not within an iFrame
Fixed z-index of search results dropdown #2626
Merge pull request #2632 from howdyitshelena/2626

Fixed z-index of search results dropdown #2626
Fixed points bubble on content wrapper #2627

Made the points bubble to only show when there are points, which also
only shows when users are logged in.