Various fixes to index.html and search.html

Changes:
-Set the bottom-border to green for navbar links on hover (also adjust padding to fit the stripe)
-Changed active navbar item's background-color to darker green
-Removed Weather item from navbar (search.html only)
-Fixed logo broken link
-Changed body { background-color: #333; color: #ffffff; }. Footer and page header are same color now.
-Adjusted hover effects for left sidebar (new class "sidebar-subgroup")
-Changed heading colors from black to green (which is better?)
-Imported Roboto font in index.html
-Removed spacing between carousel and hexagons in index.html
Merge origin/master