Added HTML5 semantic tags

Replaced generic divs with semantic tags to give more structured meaning
Replaced footer selectors from class to element

In keeping with semantic markup, also adds more specificity
Wrapped name (navbar-brand) anchor in h1

Since the name is the most important detail and since it is first, it is
appropriate to apply the first heading to it
Replaced h3 with h2 in index page

Replaced h3 with h2 for the news section since it was being used based
on size and not hierarchical position as it should be.

Also removed the "lead" class from the introduction since it creates
extra space between the text and the navbar.