Merge pull request #2550 from Microsoft/separateCompilation

Relax import/export elision rules for separate compilation

src/compiler/commandLineParser.ts

@@ -109,6 +109,10 @@ module ts {
             type: "boolean",
             description: Diagnostics.Do_not_emit_comments_to_output,
         },
+        {
+            name: "separateCompilation",
+            type: "boolean",
+        },
         {
             name: "sourceMap",
             type: "boolean",