Replace mentions of IE7 (#4004)

IE7 is a very old browser. This PR replaces the description of IE7 with
what is considered reasonable.

---------

Co-authored-by: Alastair Campbell <ac@alastc.com>

Author: momdo

techniques/general/G142.html

@@ -6,7 +6,7 @@
       <p>This technique requires that the zoom function preserve all spatial relationships on the page and that all functionality continues to be available.</p>
    </section><section id="examples"><h2>Examples</h2>
       <ul>
-         <li>Internet Explorer 7 and Opera 9 provide a zoom function that scales HTML/CSS page content uniformly.</li>
+         <li>Most modern browsers provide a zoom function that scales HTML/CSS page content uniformly.</li>
          <li>To allow users to resize text, Adobe Reader provides a magnification tool that scales PDF pages uniformly.</li>
       </ul>
    </section><section id="tests"><h2>Tests</h2>

techniques/general/G156.html

@@ -6,7 +6,7 @@
       <p>Note that overriding the foreground and background colors of all text on a page may hide visual clues to the grouping and organization of the Web page, making it much more difficult to understand and use. This technique may not be appropriate when background colors are used to delineate areas of the page. This technique may be appropriate for technologies and user agents that do not alter border colors when background colors are overridden. If background colors are used to delineate areas of the page, "<a href="../css/C23">Specifying text and background colors of secondary content such as banners, features and navigation in CSS while not specifying text and background colors of the main content</a>" may be used to permit the user to control the colors of the main text while retaining the visual structure of the Web page.</p>
    </section><section id="examples"><h2>Examples</h2>
       <ul>
-         <li>A Web page is designed using HTML and CSS to specify the foreground and background colors. The user sets their own colors in Internet Explorer 7 and they can view the content with their chosen foreground and background colors.</li>
+         <li>A Web page is designed using HTML and CSS to specify the foreground and background colors. The user sets their own colors in the browser and they can view the content with their chosen foreground and background colors.</li>
          <li>A Web page is designed using HTML and CSS. There is a link on the page to instructions on how to set colors in various browsers.</li>
       </ul>
    </section><section id="tests"><h2>Tests</h2>