Renamed PostPublisher DSO as BlogPostAdder

Only change other than its own code and specs was to the
`PostCreatorAndPublisher` DSO. Back to green bar. Next up; changing the
functionality to reflect the name change.

RSpec: 724 examples, 0 failures (but see Issue #87)
RuboCop: 151 files inspected, no offenses detected
Expanded PostCCO spec and fixed PostData factory.

Spec for `PostCCO` now (exhaustively) checks saved/new posts as well as
public/draft posts. Actual new code for specs essentially limited to
`#from_entity` specs.

PostData factory now properly separates saved/new post status from
draft/public post status.

RSpec: 721 examples, 0 failures (but see Issue #87)
RuboCop: 151 files inspected, no offenses detected
Starting replacement Post CCO and specs.

What was the problem with the old one? Posts commingle the concepts of
publication, persistence and attachment to a Blog, courtesy of the
original Book-driven implementation. We've got to prise those apart
from each other, and the Superglue has resisted the first half-dozen
attempts not pushed here. Onward!

RSpec: 734 examples, 0 failures (but see Issue #87)
RuboCop: 153 files inspected, no offenses detected
More on replacement Post CCO and specs.

Post implementation-to-entity conversion now handles slug properly. The
main effort this commit went to creating a group of shared examples for
the PostCCO#to_entity method that let us concisely describe the salient
expectations in each context.

RSpec: 763 examples, 0 failures (but see Issue #87)
RuboCop: 153 files inspected, no offenses detected
Replacement PostCCO knows new public posts.

Also updated most CCO2 shared examples so that the Post entity is added
to a Blog entity.

RSpec: 773 examples, 0 failures (but see Issue #87)
RuboCop: 153 files inspected, no offenses detected
Fixed typo in "a saved entity" shared example.

Oops. That is all.

Or *almost* all; I have no idea why RSpec now reports 771 examples run
as compared to the previous 773. But the coverage report says we're
still good, and Issue 87 says the example count is a dubious number
that should be taken with a Gibraltar-sized grain of salt. Oh well.

RSpec: 771 examples, 0 failures (but see Issue #87)
RuboCop: 153 files inspected, no offenses detected
Replacement PostCCO knows invalid new public posts

RSpec: 780 examples, 0 failures (but see Issue #87)
RuboCop: 153 files inspected, no offenses detected
Almost done with PostCCO2#to_entity specs.

Only bit remaining is the second `params` hash parameter, which will be
used (initially) to inject a `Blog` entity instance into the new Post
entity.

RSpec: 798 examples, 0 failures (but see Issue #87)
RuboCop: 153 files inspected, no offenses detected
Finished specs for PostCCO2

Also pulled logic of `PostCCO2#to_entity` method out into separate
class. Will move to own file soon.

RSpec: 802 examples, 0 failures (but see Issue #87)
RuboCop: 153 files inspected, no offenses detected
First whack at PostCCO2.from_entity and specs.

First couple of specs for a new draft Post (entity), and adding a
custom matcher (`have_same_basic_content_fields_as`).

RSpec: 806 examples, 0 failures (but see Issue #87)
RuboCop: 154 files inspected, no offenses detected
PostCCO2.to_entity for new draft posts works.

Yanked just-added custom matcher; now leaning towards shared examples
in the style of those created for `from_entity`. Pffft.

RSpec: 808 examples, 0 failures (but see Issue #87)
RuboCop: 153 files inspected, no offenses detected
PostCCO2.to_entity for saved draft posts, first go

Shared examples coming soon.

RSpec: 814 examples, 0 failures (but see Issue #87)
RuboCop: 153 files inspected, no offenses detected
PostCCO2.from_entity specs completed.

Now to put them on a diet.

RSpec: 826 examples, 0 failures (but see Issue #87)
RuboCop: 153 files inspected, no offenses detected
PostCCO2 specs "diet", Part 1

Compare the specs for `PostCCO2.to_entity` with those for
`PostCCO2.from_entity`. Which are clearer, easier to read, more
navigable? Part 2 will rework the `to_entity` specs in line with the
style of those for `from_entity`.

RSpec: 820 examples, 0 failures (but see Issue #87)
RuboCop: 153 files inspected, no offenses detected
Starting to add PostCCO2 shared examples.

WIP.

RSpec: 823 examples, 0 failures (but see Issue #87)
RuboCop: 153 files inspected, no offenses detected
PostCCO2 complete.

Now to have it replace PostCCO and we're done with Issue #100. Finally.

RSpec: 785 examples, 0 failures (but see Issue #87)
RuboCop: 153 files inspected, no offenses detected
[Closes #100] Moved PostCCO2 to PostCCO.

Breaking a support class out to its own file along the way.

RSpec: 767 examples, 0 failures (but see Issue #87)
RuboCop: 152 files inspected, no offenses detected
Merge pull request #104 from jdickey/issue-100-stage3

Stage 3 of effort to close Issue #100. It's always the "simple" things that stop you cold.

RSpec: 767 examples, 0 failures (but see Issue #87)
RuboCop: 152 files inspected, no offenses detected