[css3-fonts] yup, another wording tweak of map class methods

Author: John Daggett

css-fonts/Fonts.html

@@ -5807,9 +5807,9 @@ <h3 id=om-fontfeaturevalues><span class=secno>8.2 </span>The <a
    title="feature_value_block">feature value block</i></a> and so forth.
 
   <p>The <code>CSSFontFeatureValuesMap</code> interface uses the <a
-   href="http://dev.w3.org/2006/webapi/WebIDL/#es-map-members">default
-   methods of map class</a> but the <code>set</code> method takes a sequence
-   of unsigned integers and associates it with a given
+   href="http://dev.w3.org/2006/webapi/WebIDL/#es-map-members">default map
+   class methods</a> but the <code>set</code> method has different behavior.
+   It takes a sequence of unsigned integers and associates it with a given
    <code>featureValueName</code>. The method behaves the same as the default
    map class method except that a single unsigned long value is treated as a
    sequence of a single value. The method throws an exception if an invalid