Rename namespace class to {package.name}Package

Conflicts:

	compiler/jet.as.java.psi/src/org/jetbrains/jet/asJava/JavaElementFinder.java

compiler/testData/compileJavaAgainstKotlin/method/Hello.java

@@ -1,6 +1,6 @@
 
 class Hello {
     public static void xx() {
-        String s = namespace.f();
+        String s = _DefaultPackage.f();
     }
 }