Support variable substitution in CDATA of included <sql />

Follow-up to #331

Author: harawata

src/main/java/org/apache/ibatis/builder/xml/XMLIncludeTransformer.java

@@ -81,7 +81,7 @@ private void applyIncludes(Node source, final Properties variablesContext, boole
       for (int i = 0; i < children.getLength(); i++) {
         applyIncludes(children.item(i), variablesContext, included);
       }
-    } else if (included && source.getNodeType() == Node.TEXT_NODE
+    } else if (included && (source.getNodeType() == Node.TEXT_NODE || source.getNodeType() == Node.CDATA_SECTION_NODE)
         && !variablesContext.isEmpty()) {
       // replace variables in text node
       source.setNodeValue(PropertyParser.parse(source.getNodeValue(), variablesContext));

src/test/java/org/apache/ibatis/submitted/include_property/Mapper.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!--
 
-       Copyright 2009-2018 the original author or authors.
+       Copyright 2009-2019 the original author or authors.
 
        Licensed under the Apache License, Version 2.0 (the "License");
        you may not use this file except in compliance with the License.
@@ -26,9 +26,9 @@
     col_c
   </sql>
 
-  <sql id="colsSuffix">
+  <sql id="colsSuffix"><![CDATA[
     col_${suffix}
-  </sql>
+  ]]></sql>
 
   <sql id="colsPrefix">
     ${prefix}a