Add support for interacting with Remote R sessions

Add support for interacting with running remote R sessions, such as RGui or RStudio. Requires and uses the R svSocket package to make requests and marshal data to/from the remote R session. Also, provides a remote R type provider.

The remote R session type provider support requires a different syntax than the original R type provider due to current limitations in the FSharp compiler. A future version of the FSharp compiler should support type extensions generated by type providers; this expected improvement in the compiler will enable the remote R type provider to provide a syntax and development experience much closer to the original local R session type provider.