Provide flag to ignore errors

We perform releases and report generation of our codebase at the same time. We've had numerous releases fail due to communication issues with the Sun server while trying to retrieve the Java package list. Even though this is no fault of the plugin, I'd love to have a flag where I could tell the plugin to just ignore the error and go on. Sure, we'll lose the Javadoc out of our reports, but at least the release will complete. And if we really want that Javadoc in there later, we can re-run the reports at a later date.