Changelog:

• restore the behavior from before 0.8.x series when only methods returning Unit could be considered setters (provides a better fix to #424, fixed in #485). If needed non-Unit setters can be opted-in
• detect and report ambiguities with pairing field names (#449, #461, fixed in #485)
• improve error messages when there are def methods or other inherited accessors that could be enabled with a flag (fixed in #485)

This pre-release is the fourth of the planned series of internal cleanups. The series is intended to make sure that when 1.0.0 is finally released it will not have any serious (known) issues that could be only addressed by breaking the backward compatibility. We will be really glad if you tested it, and let us know about any such issues while they are still easy to fix.