Fixed null in exception message when a stack parameter is null.
Fixed client-side handling of exception details.
Refactored message details - made them immutable, added JAXB annotations, removed messageless constructors.
Merge branch 'master' of gitorious.ow2.org:~xlcloud-continuous-integration/xlcloud/xlcloud-ci
Refactored messages - they cannot be immutable due to JAXB deserialization.
Merge branch 'master' of gitorious.ow2.org:~xlcloud-continuous-integration/xlcloud/xlcloud-ci