display message if extension version is not correct

In the optional package deployment, if the version format is not correct a
message should be sent to the java console telling the extension writer (deployer) that he/she did not use the correct versioning format. And that the problem should be fixed in order for optional package deployment to work properly. Otherwise the users will have to keep installing the extension every time the applet is visited.

With this message warning the extension writer will know there is a problem with
his/her extension applet before they stage it.