Tidy up rest-entity template.

Brace goes on a new line in an entity as the ?> swallows the new line, so we need to put our own one in.
Remove extra blank line between namespace and class.
Set ArraySerializable hydrator as the default for a new REST entity

Create a hydratorName property on the RestServiceEntity so that it can
be overridden to null or a different hydrator.
Update the skeleton to implement the ArraySerializableInterface and
create stub functions if the ArraySerializable hydrator is used.
Merge pull request #25 from akrabat/default-hydrator2

Set ArraySerializable hydrator as the default for a new REST entity
[#25] Update test case

- Since hydrator is being set by default now, expectation needed to be
  updated to add it.
Merge branch 'feature/25'

Close #25