DEPL-4789: Provide better error message if Version is missing in jenkins configuration.
Introduced DeployitPluginException and added various error checks.
DEPL-6371: throw more meaningful exception when there is no deployable
defined. Handle cause of the InvocationTargetException instead of
InvocationTargetException in PluginFirstClassloaderInvocationHandler.
DEPL-6924: Set default values on objects created with DeployitDescriptorRegistry.newInstance.
DEPL-6949: add properties required by the DarPackager/ManifestWriter even if they don't exist on XLD
Upgraded dependencies to XLD 4.5.1.
Added license header and nicer error messages.
DEPL-4899: Introduced RemotePropertyDescriptor shadow class that has support for hidden properties.
DEPL-6974: PreemptiveAuthenticationInterceptor marked as serializable.
DEPL-6974: Removed SlaveRemoteDescriptorRegistry - plugin now uses DeployitServer.getDescriptorRegistry() to initialize remote booter.