Closes gh-333

Closes gh-330

Closes gh-328

See gh-328

Closes gh-326

See gh-326

- use petclinic as the db name and root password

Fixes #322

Closes gh-319

Closes gh-303

Closes gh-301

Fixes gh-267

correct testProcessCreationFormHasErrors method's post url

previously the div.control-group and the containing input shared the same id

Closes gh-229

Encapsulation is better that way (and tere is a getter for all of them
anyway).

It's better maintained and it seems to provide more features
as well.

Vet, Owner, Visit. The Visit "aggregate" is a little artificial
but it demonstrates a useful point about not holding on to
references of "parent" (reference data) objects, i.e. the Visit has
an Integer petId, instead of a Pet field. In principle this app is
now almost ready to migrate to multiple services if anyone wanted
to do that.