Updated models used by serializer tests to include complex types and added more test coverage for serialization and deserialization.  Also included are several tests that deserialize from a hard coded base64 encoded String to ensure we don't break backwards compatibility.  Tests are also added to verify cycles in POCO entities, lazy loading proxies, and change tracking proxies.
Support in runtime for creating CSpace association types and ssets
IAwaitYourComment - xml doc comments for async APIs

 - Polishing/completing xml doc comments for public asnyc API surface.
 - Tried to standardized with comments from non-async APIs where possible and also keep a consistent set of terminology and wording throughout our product
 Adds interception infrastructure supporting capturing, modification and cancellation of several aspects of the sync update pipeline.

 - New IDbInterceptor interface supporting the following hooks: CommandExecuting, ConnectionOpening and CommandTreeCreated.
 - Interception implemented via new intercepting decorators for DbCommand and EntityConnection.
 - Interceptors registered and dispatched via a new global, threadsafe singleton class: "Interception".
 - Interceptors may be global or per-context instance. Latter is implemented via a ThreadLocal that gets set when a context is inside sync SaveChanges.
 - Removes DbConfiguration based command interception stuff (superceded by this change). Intercepted DbCommands are now mutable.
Removing empty test files
Merge branch 'master' of https://git01.codeplex.com/entityframework