Fixed compilation for new projects

The problem was:
 IDEA passes a DummyCompilerContext, whose project is null
 As a result, a freshly created "Hello, world" didn't run (failed with NoClassDefFound, because the compiler didn't emit any code)

idea/src/org/jetbrains/jet/plugin/compiler/JetCompiler.java

@@ -62,7 +62,7 @@ public class JetCompiler implements TranslatingCompiler {
             return false;
         }
         Project project = compileContext.getProject();
-        if (project == null || JsModuleDetector.isJsProject(project)) {
+        if (project != null && JsModuleDetector.isJsProject(project)) {
             return false;
         }
         return true;