http://jira.codehaus.org/browse/GROOVY-5003

Use stock gmaven plugin to achieve this

happen.

This happens because the version number isn't computed yet, but we try
to put that into HTTP header.

Fixing this by making <st:header/> tolerate null in value or name.

This reverts commit 0ef9424d.

Functioning JDK installation after the Oracle site change. They now put binaries behind SSO, so we need a real HTML scraper to be able to get past this, hence the htmlunit dependency.