[css3-color] Don't use SVG-specific terminology in the definition of opacity.

This is already reflected in
http://www.w3.org/Style/2011/REC-css3-color-20110607-errata.html
and was resolved in
http://lists.w3.org/Archives/Public/www-style/2011Jul/0094.html

Author: dbaron

css3-color/Overview.html

@@ -527,9 +527,11 @@ <h3 id=transparency><span class=secno>3.2. </span>Transparency: the ‘<a
    <dd>Syntactically a &lt;number&gt;. The uniform opacity setting to be
     applied across an entire object. Any values outside the range 0.0 (fully
     transparent) to 1.0 (fully opaque) will be clamped to this range. If the
-    object is a container element, then the effect is as if the contents of
-    the container element were blended against the current background using a
-    mask where the value of each pixel of the mask is &lt;alphavalue&gt;.
+    object has children, then the effect is as if the children were blended
+    against the current background using a mask where the value of each pixel
+    of the mask is &lt;alphavalue&gt;. For SVG, ‘has children’ is
+    equivalent to being a container element <a href="#SVG11"
+    rel=biblioentry>[SVG11]<!--{{SVG11}}--></a>.
   </dl>
 
   <p>Since an element with opacity less than 1 is composited from a single

css3-color/Overview.src.html

@@ -331,10 +331,13 @@ <h3 id="transparency">Transparency: the 'opacity' property</h3>
       <dd>Syntactically a &lt;number&gt;. The uniform opacity setting to be applied across an entire object.
       Any values outside the range 0.0 (fully transparent) to 1.0 (fully
       opaque) will be clamped to this range. 
-      If the object is a container element,
-      then the effect is as if the contents of the container element
+      If the object has children,
+      then the effect is as if the children
       were blended against the current background using a mask where the
-      value of each pixel of the mask is &lt;alphavalue&gt;.</dd>
+      value of each pixel of the mask is &lt;alphavalue&gt;.
+      For SVG, &lsquo;has children&rsquo; is equivalent to being a
+      container element [[SVG11]].
+      </dd>
 
 </dl>