misc/notepadplus: Fix Function List in Notepad++ 6.5

Since version 6.5, npp change the Function List syntax for User Defined Languages.
We need use userDefinedLangName syntax in association tag in Notepad++ 6.5.

Fix issue 6735.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/22770043

misc/notepadplus/functionList.xml

 <!-- <NotepadPlus> -->
 	<!-- <functionList> -->
 		<!-- <associationMap> -->
+
+		<!--
+			if npp version == 6.4:
 			<association ext=".go" id="go"/>
 
+			if npp version >= 6.5:
+			<association userDefinedLangName="go" id="go"/>
+		-->
+
 		<!-- </associationMap> -->
 		<!-- <parsers> -->
 			<parser id="go" displayName="Go" commentExpr="((/\*.*?\*)/|(//.*?$))">