Rename namespace class to {package.name}Package

Conflicts:

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

compiler/testData/codegen/regressions/kt864.jet

@@ -9,7 +9,7 @@ World""");
 
   fun box() : String {
     // TODO compiler error
-    // both these expressions causes java.lang.NoClassDefFoundError: collections/namespace
+    // both these expressions causes java.lang.NoClassDefFoundError: collections/CollectionPackage
     val list1 = sample().useLines{it.toArrayList()}
     val list2 = sample().useLines<ArrayList<String>>{it.toArrayList()}