Raven build 2.5.2700

Hi,

I've updated the Raven LinqPad driver to the latest stable version of Raven (2.5.2700).

#### Highlights
* IDocumentSession and IDocumentStore had some new methods which had to be implemented. Trivial as the decorator just delegates to the underlying session and store.
* Removed bin & obj folders which were still present because the .gitignore file was added after they'd been committed. This has been greatly inflating the repo because the temporary files and dlls would be updated every commit.
* Removed packages since package restore is on.
* Updated to most recent packages.
* Created new signing keys as the originals were password-protected.

Cheers,

Mike.