Fix home link not having a class of active on home page.

Changes logic in header on how page title gets set. Now checks for the
page title being set to "Home" and sets the format to "site.title •
site.tagline"

All other pages get set to "page.title • site.title"
Merge pull request #13 from mrmrs/home-link-hilite

Fix home link not having a class of active on home page.