Update frontpage to be use graphics.

Use graphical icons in the front page, and reduce text. Added a custom
CSS file for the styling.
Reorganize images and static folder.

Reorganize to have the following hierarchy, of folders for static
content.

  content
   + static
     + css
     + images
Merge pull request #8 from bravegnu/customize-frontpage

Update frontpage to use graphics.