Minimal refactoring that eliminates importing Java's root namespace by default.

All tests pass. Some beautifying needed

#KT-1477 Fixed

compiler/backend/src/org/jetbrains/jet/codegen/CodegenContext.java

@@ -84,6 +84,9 @@ public abstract class CodegenContext {
         while(true) {
             DeclarationDescriptor contextDescriptor = c.getContextDescriptor();
             if(!(contextDescriptor instanceof ClassDescriptor) && !(contextDescriptor instanceof NamespaceDescriptor)) {
+                if (c.getParentContext() == null) {
+                    System.out.println();
+                }
                 c = c.getParentContext();
             }
             else {

compiler/backend/src/org/jetbrains/jet/codegen/NamespaceCodegen.java

@@ -52,7 +52,7 @@ public class NamespaceCodegen {
     }
 
     public void generate(JetFile file) {
-        NamespaceDescriptor descriptor = state.getBindingContext().get(BindingContext.NAMESPACE, file);
+        NamespaceDescriptor descriptor = state.getBindingContext().get(BindingContext.FILE_TO_NAMESPACE, file);
         final CodegenContext context = CodegenContext.STATIC.intoNamespace(descriptor);
 
         final FunctionCodegen functionCodegen = new FunctionCodegen(context, v, state);