Added new User table per first step of 111.

RSpec: 812 examples, 0 failures (but see Issue #87)
RuboCop: 152 files inspected, no offenses detected
First whack at User DAO.

Bearing a remarkable similarity to the existing UserData ActiveRecord
model (minus most business-aware logic beyond barest validation), this
is really straightforward. Unlike the earlier class, this one *does
not* have a `registered` scope depending on an ID greater than one; the
concept of a Guest User is exclusively at a higher level now.

RSpec: 822 examples, 0 failures (but see Issue #87)
RuboCop: 154 files inspected, no offenses detected
Added new Posts table preparatory to DAO.

RSpec: 822 examples, 0 failures (but see Issue #87)
RuboCop: 154 files inspected, no offenses detected
PostDAO, spec and factory.

RSpec: 822 examples, 0 failures (but see Issue #87)
RuboCop: 154 files inspected, no offenses detected
UserEntity code/specs per Step 2 of The Plan.

See Issue #111.

RSpec: 839 examples, 0 failures (but see Issue #87)
RuboCop: 158 files inspected, no offenses detected
PostEntity code/specs per Step 2 of The Plan.

This concludes Step 2. Pinging Issue #111.

RSpec: 849 examples, 0 failures (but see Issue #87)
RuboCop: 160 files inspected, no offenses detected
Fixed bug in entity init; broke out to new class.

Breezing right along with a deceptively green bar until we get to
entity factories (see next commit), which were unable to create
Post/UserEntity instances with expected instance variables. Further
poking led to a fix, which led to breaking out common code into a new
shared class that has been (temporarily!) stuck into the `lib`
directory. Whee!

RSpec: 849 examples, 0 failures (but see Issue #87)
RuboCop: 161 files inspected, no offenses detected
Cleanup for entities from last commit.

Also added specs for `InstanceVariableSetter` class.

RSpec: 851 examples, 0 failures (but see Issue #87)
RuboCop: 162 files inspected, no offenses detected
New entity-factory classes and specs.

This concludes Step 3 of The Plan; see Issue #111.

RSpec: 855 examples, 0 failures (but see Issue #87)
RuboCop: 166 files inspected, no offenses detected
StoreResult support class needed for Repository

As the source says, "a dirt-simple little value object".

RSpec: 857 examples, 0 failures (but see Issue #87)
RuboCop: 168 files inspected, no offenses detected
Added ErrorFactory code and specs.

RSpec: 860 examples, 0 failures (but see Issue #87)
RuboCop: 170 files inspected, no offenses detected
Inadvertent omission from ErrorFactory spec.

RSpec: 861 examples, 0 failures (but see Issue #87)
RuboCop: 170 files inspected, no offenses detected
First stab at UserRepository code and specs.

This covers initialisation and the `#add` public method, as well as
handing back correct `StoreResult` instances for success and failure.

Also corrected the `ErrorFactory` code and specs, and added
`be_saved_entity_for` custom RSpec matcher.

RSpec: 866 examples, 0 failures (but see Issue #87)
RuboCop: 174 files inspected, no offenses detected
More UserRepository error checking: record not found -- and more

Also:
* Added UserRepository#update;
* Implemented what I hope is the final-for-now fix to ErrorFactory's
.create method (assuming that the input quacks sufficiently like an
ActiveModel::Errors object), along with a long description that, if
you're reading this, you probably want to give ErrorFactory a fresh read
too;
* Added UserRepository#find_by_slug; handy to stub for testing;
* Added :be_an_error_has_for custom matcher, for testing ErrorFactory.

RSpec: 872 examples, 0 failures (but see Issue #87)
RuboCop: 175 files inspected, no offenses detected
Bugfixing in UserRepository#find_by_slug

…and thus in `#update` as well.

RSpec: 874 examples, 0 failures (but see Issue #87)
RuboCop: 175 files inspected, no offenses detected
Added UserRepository#all method and specs.

RSpec: 879 examples, 0 failures (but see Issue #87)
RuboCop: 175 files inspected, no offenses detected
UserRepository and specs completed.

Last action to be added (of those now known) was `#delete`; see the
comment from 12 August at 02:34 GMT on Issue #111 for a discussion.
Also did basic reordering cleanup.

RSpec: 881 examples, 0 failures (but see Issue #87)
RuboCop: 175 files inspected, no offenses detected
Cleanup; we need Post AND` User entity verifiers.

Calling the entity-verifier matcher for Posts simply
`be_saved_entity_for` was a mistake.

Also started breaking shared examples out of `user_repository_spec`
that will be used for the (imminent) `post_repository_spec` as well.

RSpec: 883 examples, 0 failures (but see Issue #87)
RuboCop: 176 files inspected, no offenses detected
FIrst whack at PostRepository class and specs.

RSpec: 890 examples, 0 failures (but see Issue #87)
RuboCop: 178 files inspected, no offenses detected
Repository #add shared specs.

UserRepository and PostRepository had *broadly* similar specs doing
identical functionality testing; that's been factored out into a shared
example that both now use, with appropriate RSpec variables set for the
specifics.

RSpec: 890 examples, 0 failures (but see Issue #87)
RuboCop: 178 files inspected, no offenses detected