User Profile enhancements:

- Added PreloadStore support to avoid duplicate requests
- preliminary SEO
- Support for opengraph/twitter cards
Fixes broken jasmine test - PreloadStore now returns null
copyedits
First stab at oneboxing of meta.discourse.org
Oops escape everything but image urls
Robin sucks at merging! This fixes a n+1 query.
Version bump to 0.8.3
wrong conditional