Improve Lucene Search page to be as good as the default search

Things to improve:

• On first startup the lucene search returns empty results till the index is built. We need to tell the user when the index is being built or rebuilt so that they know what's happening.
• Add space selection as for the default search
• Add RSS feeds on search query as for the default search
• Sometimes Lucene returns results twice with a different score (this needs another jira issue when fixing it)
• Need user guide on xwiki.org about Search queries with new Lucene syntax: "*" for all, etc. as this is different from the default search.
• Missing page titles in the results list as for the default list
• Remove filter for score
• Velocity errors/warns to remove when clicking on the Rebuild button
• Ensure that the index is not created in the OS temp dir as it'll be deleted on reboot!
• 2 images are added as attachements and 2 others are in the skin. I think application resources should be located either on the paid requiring them as attachments or on some resource page for that application. I don't think they should go in the skin though as applications should be independent of the skin.