Changes to site banner/masthead, including:
- Adding masthead widget area, to support logo and "Give Now" button
- Converting site title to hard-coded HTML, because line breaks and coloring need greater control
- Adding Google Font "Montserrat" as proxy for Gotham until we buy it
- Lots of CSS style changes

Signed-off-by: Matt Bernhardt <mjbernha@mit.edu>
Removing site navigation, compacting spacing between banner and site content

Signed-off-by: Matt Bernhardt <mjbernha@mit.edu>