Added Wisper Gem back into Gemfile.

RSpec: 697 examples, 0 failures (but see Issue #87)
RuboCop: 153 files inspected, no offenses detected
Eliminated BlogHelper#entries_for

This also eliminated an RSpec shared_examples block which contained the
(easily parameterisable) specs for that method.

RSpec: 684 examples, 0 failures (but see Issue #87)
RuboCop: 152 files inspected, no offenses detected
`Blog` no longer dependent on `BlogData`.

The `BlogData` implementation model never had much to do besides supply
the one-and-only title and subtitle; we're now injecting that into the
`Blog` entity, with defaults so nothing else breaks. We should be able
to now completely remove the `BlogData` model, related code such as
it's CCO and BLO, and the database table itself.

RSpec: 688 examples, 0 failures (but see Issue #87)
RuboCop: 152 files inspected, no offenses detected
BLO::BlogDataBoundary eliminated from BlogCCO.

Replaced with new BlogEntityPostLoader DSO. Note that both the
passed-in Blog instance and the entries added to it are entities.

RSpec: 691 examples, 0 failures (but see Issue #87)
RuboCop: 154 files inspected, no offenses detected
Fixing typo in updated Blog entity.

We'd previously forwarded attribute accessors for `:title`, `:subtitle`
and `:entries` to a `BlogData` instance, which is no longer used here.
This was the easy part of "getting rid of" `BlogData`. More
complicated, as noted earlier, is going to be moving the
`BlogDataDecorator#summarise` method, called by the blog index view.
Should we just transplant that method to the`BlogHelper` module? Should
we break down and add "real" pagination?

RSpec: 691 examples, 0 failures (but see Issue #87)
RuboCop: 154 files inspected, no offenses detected
Killed :policy_scoped on BlogController.

That was the easy part, as expected.

Moving the #summarise method from BlogDataDecorator (which no longer
applies unless we assign `@blog`) to, e.g., `BlogHelper` wasn't the fix
we were looking for. The rethink continues.

RSpec: 691 examples, 0 failures (but see Issue #87)
RuboCop: 154 files inspected, no offenses detected
BlogDataDecorator discombobulated.

As BlogData (the implementation model) is on its way out,
removing/moving dependencies and interactions. Here, the shifted code
was the former BlogDataDecorator#summarise method, moved (at least
temporarily) to BlogHelper#summarise_blog.

More to come.

RSpec: 691 examples, 0 failures (but see Issue #87)
RuboCop: 154 files inspected, no offenses detected
BlogDataDecorator gone. Aftershocks minimal.

BlogController code/specs and blog-index view spec the only code that
cared. Past tense, now.

RSpec: 689 examples, 0 failures (but see Issue #87)
RuboCop: 152 files inspected, no offenses detected
Deleted BlogDataBoundary code and specs.

Halfway done with 92, after getting nearly mortally sidetracked.

RSpec: 683 examples, 0 failures (but see Issue #87)
RuboCop: 150 files inspected, no offenses detected
[Fix #92] BLO removal completed.

Both previously-existing BLOs removed; all specs pass; a significant
"what am I forgetting?" delay yielded no results.

The "decouple using Wisper" part of the issue, though with an obvious
(and explicitly marked; see
https://github.com/jdickey/new_poc/blob/3bc96b9/app/controllers/posts_co
ntroller.rb#L43-L51) candidate for such decoupling, is once again
deferred to Issue #95).

RSpec: 678 examples, 0 failures (but see Issue #87)
RuboCop: 148 files inspected, no offenses detected
Merge pull request #96 from jdickey/issue-92

[Close #92] BLO classes removed.