Support qualified namespaces.

Author: webbju

UnrealAngelscriptParser/Grammar/UnrealAngelscriptParser.g4

@@ -394,13 +394,15 @@ namespaceName: originalNamespaceName | namespaceAlias;
 originalNamespaceName: Identifier;
 
 namespaceDefinition:
-	Namespace (Identifier | originalNamespaceName)? LeftBrace namespaceBody = declarationseq
-		? RightBrace;
+	Namespace qualifiedNamespaceName? LeftBrace namespaceBody = declarationseq? RightBrace;
 
 namespaceAlias: Identifier;
 
 namespaceAliasDefinition: Namespace Identifier Assign qualifiednamespacespecifier Semi;
 
+qualifiedNamespaceName:
+    Identifier (Doublecolon Identifier)*;
+
 qualifiednamespacespecifier: nestedNameSpecifier? namespaceName;
 
 balancedTokenSeq: balancedtoken+;