Wrong Date Format for Confluence import

When reading in the entities.xml from the confluence import the ConfluenceXMLPackage uses a date format of: "yyyy.MM.dd G 'at' HH:mm:ss.SSS"

The example noted in the javadoc actually looks more like what the export format uses (at least confluence 5.3); a DateFormat like "yyyy-MM-dd HH:mm:ss.SSS" works better.

I would send a pull request, but have no idea how to fix up the "big" test data for the 4.3.2.test