start of home page redesign
Add Options for :autorun:, :above:, and :hidecode:

The autorun option will arrange for the activecode block to run after the page has been fully loaded.   the above option locates the canvas before the code in the page layout, and the hidecode option allows for the code itself to be hidden along with a toggle button.
A few more ideas to redo the new landing page.
More minor changes to index page
Fix the test for allVisualizers undefined
more work on index page aesthetics
Bug Fix:  An extra quote slipped into some feedback and caused feedback to fail on question 3.1.1
rename app_a to more descriptive errorsAndDebug
fix enumerated list warning in files.  remove trailing spaces.
Add entries for Appendices and Labs
Ignore files from the data structures book that should be ignored.

No more warnings!
Add functions to get number of online users and more cosmetic improvements to the front page.
Add controllers to return number of online users.
Add a quick help page on navigating the book.