serialize any objects as json, falling back to an object containing toString and error message if the object is not properly serializable
make js for displaying gui more consistent, using JSON.stringify rather than FormatJSON since the latter doesn't do quotes right, and stringifying activity tags
service failure detector is an enricher, in example
change JSON serialization used by REST so that it looks at fields, ignoring getters, because getters can cause infinite loops,
and fix a couple other places where JSON serialization was dodgy (streams, apidoc)
include UndeclaredThrowable as an exception which is not interesting, and whose nested exception should be preferred for the purpose of informing the user of root causes
This closes #159