Blog model and CCO::PostCCO gone.

RSpec: 935 examples, 0 failures, 32 pending
RuboCop: 219 files inspected, no offenses detected
PostCCO is gone; shared examples for it now, too.

RSpec: 935 examples, 0 failures, 32 pending
RuboCop: 205 files inspected, no offenses detected
Cutting UserDataDecorator down, 1 of 2.

`#build_profile` isn't called anywhere. `#build_index_row_for` *is*,
and it needs a transplant/rewrite using Nokogiri instead of view
helpers like `#content_tag`.

RSpec: 926 examples, 0 failures, 32 pending
RuboCop: 205 files inspected, no offenses detected