Greg Allen patches:

Checking for null in some setter methods. These get called with null parameter from Notifier.java.

Fix toXml() method for a ResourceChange.  A CollectionChange would end up with a missing end </ResourceChange> tag.

Minor change to DeletedDetailsType.java - the XML emitted included unnecessary spaces (for indentation) since the start and end tag are on the same line. I fixed it by changing the call to close the tag to use xml.closeTagNoblanks