Update to gallery_manifest.json

Proposing a new example app.(RealEstateSim)
Update index.html

Added line : 
 <li><a href="http://enyojs.com/gallery/#kmkim.RealEstateSim">Example Enyo Game App</a>
Add kmkim.RealEstateSim.jpg
Delete kmkim.RealEstateSim.jpg
Added kmkim.RealEstateSim.jpg
Merge pull request #105 from Screamo/gh-pages

Final Request : Enyo sample app added