JBIDE-17937 - Add a 'Nightly' label on N&N when it's not release yet.

mmh.. the 'Nightly' label mentionned in the JIRA label appears as a 'Coming Soon' label, but this can be changed if you don't like it..

Also, I added missing entries in products.yml for 4.1.2.CR1 and 4.1.0.CR1, which don't provide links to downloadable bits, but link to the .Final download page, instead.