Use consistent tense in changes section

Author: fantasai

css3-flexbox/Overview.html

@@ -3346,12 +3346,12 @@ <h2 class=no-num id=changes>Changes</h2>
 
   <ul>
    <li> The ‘<code class=property>display</code>’ values for flex
-    containers were changed from ‘<code class=css>flexbox</code>’ and
+    containers have been changed from ‘<code class=css>flexbox</code>’ and
     ‘<code class=css>inline-flexbox</code>’ to ‘<a href="#flex"><code
     class=css>flex</code></a>’ and ‘<a href="#display-inline-flex"><code
     class=css>inline-flex</code></a>’.
 
-   <li> The alignment properties and values were renamed to align with the
+   <li> The alignment properties and values have been renamed to align with the
     new <a href="http://www.w3.org/TR/css3-align/">Box Alignment</a> module:
     <ul>
      <li>‘<code class=property>flex-align</code>’ → ‘<a
@@ -3368,7 +3368,7 @@ <h2 class=no-num id=changes>Changes</h2>
       class=property>justify-content</code></a>’
     </ul>
 
-   <li> The ‘<code class=property>flex-order</code>’ property was renamed
+   <li> The ‘<code class=property>flex-order</code>’ property has been renamed
     to ‘<a href="#order"><code class=property>order</code></a>’, to allow
     it to be used with other layout models in the future.
 
@@ -3379,15 +3379,15 @@ <h2 class=no-num id=changes>Changes</h2>
     href="#flex-basis0"><code class=property>flex-basis</code></a>’
     longhands.
 
-   <li> Negative free space is distributed in proportion to the flex basis ×
-    flex shrink ratio, rather than just the flex shrink ratio.
+   <li> Negative free space is now distributed in proportion to <var>flex basis</var> ×
+    <var>flex shrink ratio</var>, rather than just the flex shrink ratio.
 
-   <li> Flex items are allowed to shrink by default. (The initial value of
+   <li> Flex items are now allowed to shrink by default. (The initial value of
     ‘<a href="#flex-shrink"><code class=property>flex-shrink</code></a>’
     is ‘<code class=css>1</code>’.)
 
    <li> A new <a href="#min-size-auto">‘<code class=css>auto</code>’
-    value for ‘<code class=css>min-width/height</code>’</a> was added to
+    value for ‘<code class=css>min-width/height</code>’</a> has been added to
     set a reasonable default minimum main size for flex items.
 
    <li> The <a href="#visibility-collapse">effect of ‘<code
@@ -3406,7 +3406,7 @@ <h2 class=no-num id=changes>Changes</h2>
    <li> The flex layout algorithm has received an editorial overhaul, and
     many error fixes and clarifications were made.
 
-   <li> A lot of terminology was updated to make it less confusing:
+   <li> A lot of terminology has been updated to make it less confusing:
     <ul>
      <li>flexbox → flex container
 

css3-flexbox/Overview.src.html

@@ -2670,10 +2670,10 @@ <h2 class="no-num" id="changes">Changes</h2>
 		<a href="http://www.w3.org/TR/2012/WD-css3-flexbox-20120322/">22 March 2012 Working Draft</a>:
 	<ul>
 		<li>
-			The 'display' values for flex containers were changed
+			The 'display' values for flex containers have been changed
 			from ''flexbox'' and ''inline-flexbox'' to ''flex'' and ''inline-flex''.
 		<li>
-			The alignment properties and values were renamed to align with the new
+			The alignment properties and values have been renamed to align with the new
 			<a href="http://www.w3.org/TR/css3-align/">Box Alignment</a> module:
 			<ul>
 				<li>'flex-align' &rarr; 'align-items'
@@ -2682,17 +2682,17 @@ <h2 class="no-num" id="changes">Changes</h2>
 				<li>'flex-pack' &rarr; 'justify-content'
 			</ul>
 		<li>
-			The 'flex-order' property was renamed to 'order',
+			The 'flex-order' property has been renamed to 'order',
 			to allow it to be used with other layout models in the future.
 		<li>
 			The 'flex' shorthand has been split into the 'flex-grow', 'flex-shrink', and 'flex-basis' longhands.
 		<li>
-			Negative free space is distributed in proportion to the flex basis &times; flex shrink ratio,
+			Negative free space is now distributed in proportion to <var>flex base size</var> &times; <var>flex shrink ratio</var>,
 			rather than just the flex shrink ratio.
 		<li>
-			Flex items are allowed to shrink by default. (The initial value of 'flex-shrink' is ''1''.)
+			Flex items are now allowed to shrink by default. (The initial value of 'flex-shrink' is ''1''.)
 		<li>
-			A new <a href="#min-size-auto">''auto'' value for 'min-width/height'</a> was added
+			A new <a href="#min-size-auto">''auto'' value for 'min-width/height'</a> has been added
 			to set a reasonable default minimum main size for flex items.
 		<li>
 			The <a href="#visibility-collapse">effect of ''visibility: collapse''</a>
@@ -2710,7 +2710,7 @@ <h2 class="no-num" id="changes">Changes</h2>
 			The flex layout algorithm has received an editorial overhaul,
 			and many error fixes and clarifications were made.
 		<li>
-			A lot of terminology was updated to make it less confusing:
+			A lot of terminology has been updated to make it less confusing:
 			<ul>
 				<li>flexbox &rarr; flex container
 				<li>flexbox item &rarr; flex item