Overall improvement to all pages

-Improved navbar with glyphicons for all pages
-New footer
-Browse moved inside Library (browse.html title renamed to purchase.html)
-Created main library search landing page (search.html; formerly search.html renamed to materials.html)
-Removed page heading text from materials.html (the text will now only be included in search.html)
-Fixed hyperlink anchors in materials.html
-Fixed horizontal scrollbar glitch in materials.html
-Added navigation buttons (materials, components, systems) in materials.html