Minor edits to blog post on teaching at UC Davis

This pull request includes minor editors to `blog/2014/10/uc_davis_physics7.html`, plus all the changes made to `master` since @abostroem last updated. Please look at the former, and if you like the changes, merge into your branch - your pull request against `swcarpentry/site` will be updated automatically, and @gvwilson will then merge and publish.