jQuery.data: correct info on .data( "name", undefined )

Fixes gh-586
Closes gh-673

Author: AurelioDeRosa

entries/jQuery.data.xml

@@ -25,7 +25,7 @@ jQuery.data( document.body, "bar", "test" );
       </code></pre>
     </longdesc>
     <note id="no-data-on-xml" type="additional"/>
-    <note id="data-doesnt-accept-undefined" type="additional" data-title="jQuery.data" data-parameters="el, &quot;name&quot;"/>
+    <note id="jquery-data-doesnt-accept-undefined" type="additional" data-title="jQuery.data" data-parameters="el, &quot;name&quot;"/>
     <example>
       <desc>Store then retrieve a value from the div element.</desc>
       <code><![CDATA[

notes.xsl

@@ -2,7 +2,10 @@
 <xsl:template name="note">
 	<xsl:choose>
 		<xsl:when test="@id = 'data-doesnt-accept-undefined'">
-			<code>undefined</code> is not recognised as a data value. Calls such as <code><xsl:value-of select="@data-title" />( <xsl:value-of select="@data-parameters" />, undefined )</code> will return the corresponding data for "name", and is therefore the same as <code><xsl:value-of select="@data-title" />( <xsl:value-of select="@data-parameters" /> )</code>.
+			<code>undefined</code> is not recognized as a data value. Calls such as <code><xsl:value-of select="@data-title" />( <xsl:value-of select="@data-parameters" />, undefined )</code> will return the jQuery object that it was called on, allowing for chaining.
+		</xsl:when>
+		<xsl:when test="@id = 'jquery-data-doesnt-accept-undefined'">
+			<code>undefined</code> is not recognized as a data value. Calls such as <code><xsl:value-of select="@data-title" />( <xsl:value-of select="@data-parameters" />, undefined )</code> will return the corresponding data for "name", and is therefore the same as <code><xsl:value-of select="@data-title" />( <xsl:value-of select="@data-parameters" /> )</code>.
 		</xsl:when>
 		<xsl:when test="@id = 'dimensions-number'">
 			The number returned by dimensions-related APIs, including <code><xsl:value-of select="@data-title"/></code>, may be fractional in some cases. Code should not assume it is an integer. Also, dimensions may be incorrect when the page is zoomed by the user; browsers do not expose an API to detect this condition.