Merge pull request #2400 from Microsoft/toolsversion

Add toolsversion to shim so we can read it from VS.

src/services/shims.ts

@@ -833,3 +833,5 @@ module ts {
 module TypeScript.Services {
     export var TypeScriptServicesFactory = ts.TypeScriptServicesFactory;
 }
+
+let toolsVersion = "1.4";