Bumped RavenDB.Client version to 2.0.2230 in main provider branch.
Removed Nuget import of JSON.net, as RavenDB 2.0 internalizes this dependency.

Sample project not yet updated [see next commit].
No changes were made to the session state provider logic.
Bumped assembly version to 1.7.2230 (maybe need to bump to 2.0.2230?)

Preliminary tests with vanilla RavenDB 2.0 indicate proper functioning.
Have not verified expiration/purging of session data in Raven.
Updated sample project to use updated versions of RavenDB and the
session state provider (1.7.2230). Verified functionality against
RavenDB 2.0.

Solution/Project updated for compatibility with VS2012 (should
remain compatible with VS2010 [unverified]).