Add documentation about QtOpenGLExtensions library and its license

Change-Id: I1f22ddd4ff8cd801319cd9e3db1d35a2ab21d2d4
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>
(cherry picked from commit 2646d39b)

doc/src/modules.qdoc

@@ -159,3 +159,73 @@
     OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
     \endcode
 */
+
+/*!
+    \page qtopenglextensions.html
+    \title The QtOpenGLExtensions Library
+    \ingroup licensing
+    \brief Commercial and \l{BSD 3-clause "New" or "Revised" License}.
+
+    QtOpenGLExtensions is a library that contains auto-generated wrappers
+    for OpenGL extensions from the Khronos registry.
+
+    To include the definitions of the module, use the following directive:
+
+    \code
+        #include <QtOpenGLExtensions>
+    \endcode
+
+    To link against the module, add this line to your qmake .pro file:
+
+    \code
+        QT += openglextensions
+    \endcode
+
+    Because applications do typically use only few extensions, the library is
+    statically linked with the application. To avoid issues with
+    \l{GNU Lesser General Public License (LGPL)} in this case, the library is
+    licensed both under the commercial licenses, and the
+    \l{BSD 3-clause "New" or "Revised" License}.
+
+    \section1 License Information
+
+    \badcode
+    Commercial License Usage
+    Licensees holding valid commercial Qt licenses may use this file in
+    accordance with the commercial license agreement provided with the
+    Software or, alternatively, in accordance with the terms contained in
+    a written agreement between you and The Qt Company. For licensing terms
+    and conditions see https://www.qt.io/terms-conditions. For further
+    information use the contact form at https://www.qt.io/contact-us.
+
+    BSD License Usage
+    Alternatively, you may use this file under the terms of the BSD license
+    as follows:
+
+    "Redistribution and use in source and binary forms, with or without
+    modification, are permitted provided that the following conditions are
+    met:
+      * Redistributions of source code must retain the above copyright
+        notice, this list of conditions and the following disclaimer.
+      * Redistributions in binary form must reproduce the above copyright
+        notice, this list of conditions and the following disclaimer in
+        the documentation and/or other materials provided with the
+        distribution.
+      * Neither the name of The Qt Company Ltd nor the names of its
+        contributors may be used to endorse or promote products derived
+        from this software without specific prior written permission.
+
+
+    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+    \endcode
+*/