Extend `ObjectMapper.configOverrides()` to allow changing visibility rules

So: 2.8 added "config overrides" capability, which supports changes to 4 configuration settings for which only annotations (and for some, global settings) were available.
Based on discussions on mailing list, it seems that it might make sense to add support for equivalent of `@JsonAutoDetect` as well. This could be added in 2.9.
