Deprecate ChangeSet.fields and .fields=

[no-reply]

These methods provide a partial, asymmetrical interface to .property and .definitions. their use probably isn't reliable in general, and they don't seem to be in widespread use.

the use case they are meant to meet is bulk definition of properties. the easy alternative is my_field_list.each { |field| property(field) }.

we should deprecate this in favor of applications defining properties explicitly.