CK-13329 protecting error response setCode and setMessage methods. adding hasId() and getId() to Request interface. clean up of NamespacedRequest
CK-13329 adding Error Responses and a Server stub
Merge remote-tracking branch 'origin/master' into CK-13329_improvements

Conflicts:
	Barrister/Request.php
Merge pull request #3 from iamawongck/CK-13329_improvements

Ck 13329 improvements