[css-ui-4] Comment out examples that use prefixes

webkit prefixed animations were used in live examples to make sure they
were animated in Safari as well. Since there is no agreement in the
publication process that this is an OK thing to do, I am temporarily
commenting out the examples until we either agree that this is OK, or
agree on an alternative way to write these examples.

Author: frivoal

css-ui-4/Overview.bs

@@ -303,6 +303,7 @@ See [[WCAG]] <a href="http://www.w3.org/TR/WCAG20/#time-limits-pause">Guideline
 and <a href="http://www.w3.org/TR/WCAG20/#seizure">Guideline 2.3</a>
 for details.
 
+<!--
 <div class=example>
 	Normally, the caret blinks between on and off.
 	This makes it alternate between 2 colors.
@@ -327,7 +328,7 @@ textarea {
 		with color-alternating caret<span style="border-right: 2px solid blue;animation: caret-alternate 2s step-end infinite;-webkit-animation: caret-alternate 2s step-end infinite;"></span>
 	</div>
 </div>
-
+-->
 
 <h4 id="caret-shape">Shape of the insertion caret: 'caret-shape'</h4>
 
@@ -399,6 +400,7 @@ The stacking position of the caret is left undefined, within the following const
 	character it overlaps with is not obscured by the caret
 </ul>
 
+<!--
 <div class=example>
 	This illustrates the typical appearance of the various caret shapes.
 	In each of the sample renderings below,
@@ -430,8 +432,10 @@ The stacking position of the caret is left undefined, within the following const
 		<tr><td>''underscore''<td>Lorem ispu<span style="border-bottom: 2px solid black; -webkit-animation: caret-underscore 2s step-end infinite; animation: caret-underscore 2s step-end infinite;">m</span>
 	</table>
 </div>
+-->
 
 
+<!--
 <div class=example>
 	''caret-shape/underscore'' or ''caret-shape/block'' carets are commonly used
 	in terminals and command lines,
@@ -456,6 +460,7 @@ The stacking position of the caret is left undefined, within the following const
 	user@host:css-ui-4 $ <span style="border-bottom: 2px solid white;animation: terminal-caret 2s step-end infinite;-webkit-animation: terminal-caret 2s step-end infinite;">&nbsp;</span>
 	</pre>
 </div>
+-->
 
 <h4 id="caret">Insertion caret shorthand: 'caret'</h4>
 
@@ -475,6 +480,7 @@ This property is a shorthand for setting
 'caret-color', 'caret-animation' and 'caret-shape' in one declaration.
 Omitted values are set to their initial values.
 
+<!--
 <div class=example>
 	This example illustrates using the various caret related properties
 	in combination.
@@ -519,6 +525,7 @@ Omitted values are set to their initial values.
 	</style>
 	<div id="old-screen" style="height: 100px">&gt; <span>&nbsp;</span></div>
 </div>
+-->
 
 <h3 id="keyboard">Keyboard control</h3>