Updated project structure.

All projects are now contained in the main repository.
Added main README.md to solution.
Updated framework version for the Template site.
Added database update for comments.
Added comment mapping to the EF project.
Updated database version.
Added basic support for plugin modules.
Updated YUI-compressor package.
Updated to EF 5.0
Added support for localizing the name of Extensions.
Fixes so that Init() is called from the manager interface for Regions. This fixes issue #61.
The thumbnail-handler now supports generating thumbs for pages & posts.

The logic uses the first media-file attached to the page or post.
Added package.config to the TemplateSite.
Added the extensions project.
Added README and LICENSE to the project.
Updated Init method for precompiled websites.
Added base class for Page helpers.
Added files for the PostRegion.
Moved old entities to Entities/Internal.
Moved all entities to the core project.