Remove PHP-GTK mentions, project was abandoned (fixes #3597) (#3617)

Author: jimwins

chapters/intro.xml

@@ -79,7 +79,7 @@
     send and receive cookies. But PHP can do much more.
    </para>
    <para>
-    There are three main areas where PHP scripts are used.
+    There are two main areas where PHP scripts are used.
     <itemizedlist>
      <listitem>
       <simpara>
@@ -109,21 +109,6 @@
        for more information.
       </simpara>
      </listitem>
-     <listitem>
-      <simpara>
-       Writing desktop applications. PHP is probably
-       not the very best language to create a desktop
-       application with a graphical user interface, but if
-       you know PHP very well, and would like to use some
-       advanced PHP features in your client-side applications
-       you can also use PHP-GTK to write such programs. You also
-       have the ability to write cross-platform applications this
-       way. PHP-GTK is an extension to PHP, not available in
-       the main distribution. If you are interested
-       in PHP-GTK, visit <link xlink:href="&url.php.gtk;">its
-       own website</link>.
-      </simpara>
-     </listitem>
     </itemizedlist>
    </para>
    <para>

install/intro.xml

@@ -11,7 +11,6 @@
     <itemizedlist>
      <listitem><simpara>Websites and web applications (server-side scripting)</simpara></listitem>
      <listitem><simpara>Command line scripting</simpara></listitem>
-     <listitem><simpara>Desktop (GUI) applications</simpara></listitem>
     </itemizedlist>
    </para>
    <para>
@@ -48,16 +47,6 @@
     command line PHP applications</link>. In this case,
     you need no server and no browser.
    </para>
-   <para>
-    With PHP you can also write desktop GUI applications
-    using the PHP-GTK extension. This is a completely
-    different approach than writing web pages, as you
-    do not output any HTML, but manage windows and objects
-    within them. For more information about PHP-GTK, please
-    <link xlink:href="&url.php.gtk;">visit the site dedicated to
-    this extension</link>. PHP-GTK is not included in the
-    official PHP distribution.
-   </para>
    <para>
     From now on, this section deals with setting up PHP
     for web servers on Unix and Windows with server module