JavaDescriptorResolver refactoring

* kill JavaDescriptorResolver.typeParameterDescriptorCache
* use ClassOrNamespaceDescriptor instead of DeclarationDescriptor

Code is a bit ugly now, but simpler than before.

compiler/frontend/src/org/jetbrains/jet/lang/descriptors/ClassDescriptor.java

@@ -15,7 +15,7 @@ import java.util.Set;
 /**
  * @author abreslav
  */
-public interface ClassDescriptor extends ClassifierDescriptor, MemberDescriptor {
+public interface ClassDescriptor extends ClassifierDescriptor, MemberDescriptor, ClassOrNamespaceDescriptor {
 
     @NotNull
     JetScope getMemberScope(List<TypeProjection> typeArguments);

compiler/frontend/src/org/jetbrains/jet/lang/descriptors/ClassOrNamespaceDescriptor.java

@@ -0,0 +1,7 @@
+package org.jetbrains.jet.lang.descriptors;
+
+/**
+ * @author Stepan Koltsov
+ */
+public interface ClassOrNamespaceDescriptor extends DeclarationDescriptor {
+}

compiler/frontend/src/org/jetbrains/jet/lang/descriptors/NamespaceDescriptor.java

@@ -8,7 +8,7 @@ import org.jetbrains.jet.lang.types.NamespaceType;
 /**
  * @author abreslav
  */
-public interface NamespaceDescriptor extends Annotated, Named, DeclarationDescriptor {
+public interface NamespaceDescriptor extends Annotated, Named, ClassOrNamespaceDescriptor {
     @NotNull
     JetScope getMemberScope();