Add link to Demo Site

[aarontitus]

Original author: [email protected] (April 13, 2013 00:28:13)

When not logged in, the "Assessment Form" tab on /home should read, "Demo". "Demo" should link to demo.crisiscleanup.org
Once logged in, it should read "Assessment Form", and link to [root]

See #200, c#2

Original issue: http://code.google.com/p/sandy-disaster-recovery/issues/detail?id=229