Expose Server via an interface and remove dead code

The server needs to be exposed as an interface, because F# Interactive on Mono
doesn't seem to like DLL files referencing EXE files (so the client cannot
reference the server directly).

This also removes the (never used) option for local execution, because this would
need testing (if we need it, it can be easily recovered) & one not used function.
Added documentation as a bonus :-).

src/RProvider.DesignTime/RInteropClient.fs

@@ -8,7 +8,6 @@ open System.Diagnostics
 open System.Threading
 open Microsoft.Win32
 open System.IO
-open RProviderServer
 open RProvider.Internal
 open System.Security.AccessControl
 open System.Security.Principal
@@ -19,9 +18,6 @@ let server = "RProvider.Server.exe"
 /// Thrown when we want to show the specified string as a friendly error message to the user
 exception RInitializationError of string
 
-/// true to load the server in-process, false load the server out-of-process
-let localServer = false
-
 /// Asynchronously waits until the specifid file is deleted using FileSystemWatcher
 let waitUntilDeleted file = async {
     use watcher = 
@@ -109,7 +105,7 @@ let startNewServer() =
       p.Exited.Add(fun _ -> lastServer <- None)
 
     Logging.logf "Attempting to connect via IPC"
-    Activator.GetObject(typeof<RInteropServer>, "ipc://" + channelName + "/RInteropServer") :?> RInteropServer
+    Activator.GetObject(typeof<IRInteropServer>, "ipc://" + channelName + "/RInteropServer") :?> IRInteropServer
 
 
 /// Returns an instance of `RInteropServer` started via IPC
@@ -120,19 +116,16 @@ let getServer() =
     match lastServer with
     | Some s -> s
     | None ->
-        match localServer with
-        | true -> new RInteropServer()
-        | false ->
-            let server = startNewServer()
-            lastServer <- Some server
-            Logging.logf "Got some server"
-            server )
+        let server = startNewServer()
+        lastServer <- Some server
+        Logging.logf "Got some server"
+        server )
 
 /// Returns Some("...") when there is an 'expected' kind of error that we want
 /// to show in the IntelliSense in a pleasant way (R is not installed, registry
 /// key is missing or .rprovider.conf is missing)
 let tryGetInitializationError () =
-    try getServer().RInitValue 
+    try getServer().InitializationErrorMessage 
     with RInitializationError err -> err
 
 let withServer f =

src/RProvider.DesignTime/RProvider.DesignTime.fsproj

@@ -82,11 +82,6 @@
       <Project>{80fd4284-c7bd-4170-8cc3-41e8548402e4}</Project>
       <Private>True</Private>
     </ProjectReference>
-    <ProjectReference Include="../RProvider/RProvider.Server.fsproj">
-      <Name>RProvider.Server</Name>
-      <Project>{7ff9cfa3-2516-4970-9dd8-54c7d4ca24aa}</Project>
-      <Private>True</Private>
-    </ProjectReference>
   </ItemGroup>
   <Import Project="$(SolutionDir)\.nuget\NuGet.targets" Condition="Exists('$(SolutionDir)\.nuget\NuGet.targets')" />
   <!-- To modify your build process, add your task inside one of the targets below and uncomment it.

src/RProvider/Program.fs

@@ -1,4 +1,4 @@
-module RProviderServer.Main
+module RProvider.Server.Main
 
 open System
 open System.Diagnostics

src/RProvider/RInteropServer.fs

@@ -1,4 +1,4 @@
-namespace RProviderServer
+namespace RProvider.Server
 
 open Microsoft.FSharp.Core.CompilerServices
 open Microsoft.Win32
@@ -69,9 +69,9 @@ module internal EventLoop =
 /// Server object that is exposed via remoting and is called by the editor
 /// to get information about R (packages, functions, RData files etc.)
 type RInteropServer() =
-    inherit MarshalByRefObject()
-    
-    member x.RInitValue =
+  inherit MarshalByRefObject()
+  interface IRInteropServer with
+    member x.InitializationErrorMessage =
         // No need for event loop here, because this is initialized
         // when the event loop starts (so initResult has value now)
         match RInit.initResult.Value with
@@ -97,10 +97,6 @@ type RInteropServer() =
         EventLoop.runServerCommandSafe <| fun () ->
             getPackageDescription package
 
-    member x.MakeSafeName(name) =
-        EventLoop.runServerCommandSafe <| fun () ->
-            makeSafeName name
-
     member x.GetRDataSymbols(file) =
         EventLoop.runServerCommandSafe <| fun () ->
             let env = REnv(file) 

src/RProvider/RProvider.Runtime.fsproj

@@ -55,6 +55,7 @@
     <Compile Include="..\Common\AssemblyInfo.fs">
       <Link>AssemblyInfo.fs</Link>
     </Compile>
+    <Compile Include="RInteropInterface.fs" />
     <Compile Include="CharacterDeviceInterceptor.fs" />
     <Compile Include="Configuration.fs" />
     <Compile Include="Logging.fs" />