cattr_accessor doesn't self-inheriting subclass
cattr_accessor doesn't self-inheriting subclass

With `:instance_accessor => false`, you don't need to wrap
`cattr_accessor` in `class << self` to keep it from percolating down to
the instances, and doing so means that it doesn't even get attached as
methods to the class itself.

fhir-crucible/fhir_client,fhir-crucible/fhir_client,tambling/fhir_client,tambling/fhir_client