Statistics page-breaking fixes and layout fixes for final QA

Page breaking for statistics fixes to allow flowing of multiple features across pages with goal of maintaining a stable 1/2 inch bottom margin.  Fixes include the following:

<ul>
<li>newline tag causing very bad page breaks between feature headers. Suggestion to remove br/newline from content should be done. In many cases if not all, all spacing between elements are taken care of with margin/padding. For now display:none; has been set.</li>
<li>Debug mix-in's written by Phil to allow a debug mode to be implemented in Statistics file and also will be migrated to aid in the page breaking of Pre-Calculus.  Debug utilized to fix/view page breaking that is done in file.  Set to off for Pull request</li>
<li>Example section of statistics rectified and appears to be page breaking well 98% of time.  There are known errors outstanding with the proper breaking of tables inside examples/try-its.</li>
<li>Layout fix to utilize San-Serif font for Tables and figures in solutions.</li>
<li>Fix for Preface to include bullets in list items</li>
<li>Fix to utilize Serif font in Example solution paragraphs.</li>
</ul>