Use one head partial for blog and site

For some reason the scripts have been removed from the blog pages for a while.
Now that we're concatenating and minifying everything, load the same CSS and JS
on all pages.

fixes #122
Merge pull request #123 from robwierzbowski/rw/fix-highlighting

Use one head partial for blog and site
Re-organize media files and add simplified Yo wordmark

- Better organization of media -- source/ for vector source files, and
  optimized/ for files created from source files.
- Split character file into individual files with proper names
- Remove old unreferenced source files that aren't our responsibility to
  maintain
- Add simplified Yo wordmark