Now you can't use the same syntax as you would for a method to
implement a property as whole, instead you need to specify the
getter and/or setter explicitly. This is to allow parent classes
to expand their properties without altering behavior of the child
classes.
Previously we couldn't return a slice, instead required the user to
pass a slice and we'd fill it since Eolian couldn't generate fallbacks
for structures.
Since @q66 fixed eolian, we can now return the structure itself as
initially wanted, ditching some TODO from the code.
These interfaces allows generic operations on objects that can store
or provide data, such as a file or a buffer.
With well defined interfaces and events we can create code such as
Efl.Io.Copier, that will link a source with a destination and
progressively copy data as they appear.