Use unix fileformat for app.js

For some reason, the app.js file was using mac fileformat, which caused
strange results when running `git diff`. Diagnosed and fixed by running
the following commands in Vim:

    :set fileformat?
    mac
    :set fileformat=unix
    :write
Prevent source/bower_components from appearing in build/
Remove /{blog,episodes}/categories pages; use /categories only
Remove /episodes-all page; use only /episodes/archive