Add Elgg Version field to submission form

[brettp]

We're getting sites submitted that are based on Elgg 1.7. With the upcoming release of 1.9, there I'd hate people to look at a 1.7 site--even a well made one--and think that's current Elgg.

[brettp]

Actually, we could possibly sniff this after they enter the URL and auto-fill it. Ditto for the site name and desc.

[beck24]

What's the best way to sniff Elgg version? The elgg version metatags are easily removed, and for most of the professional sites I think they likely are.