Doc: update list of plugin base classes

Sorted by Qt module.

Change-Id: I0b701acc6c4fa863a521504ae0cd6f9fa8087d80
Reviewed-by: Venugopal Shivashankar <venugopal.shivashankar@digia.com>

doc/src/howtos/plugins-howto.qdoc

 /****************************************************************************
 **
-** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
 ** Contact: http://www.qt-project.org/legal
 **
 ** This file is part of the documentation of the Qt Toolkit.
@@ -66,27 +66,141 @@
     subclassing the appropriate plugin base class, implementing a few
     functions, and adding a macro.
 
-    Below you will find a list with the plugin base classes.
-
     There are several plugin base classes. Derived plugins are stored
     by default in sub-directories of the standard plugin directory. Qt
-    will not find plugins if they are not stored in the right directory.
+    will not find plugins if they are not stored in the appropriate directory.
 
-    \table
-    \header \li Base Class              \li Key Case Sensitivity
-
-    \row    \li QGenericPlugin,         \li Case-insensitive
-    \row    \li QGenericPluginFactory,  \li Case-insensitive
-    \row    \li QAccessiblePlugin       \li Case-sensitive
-    \row    \li QIconEnginePlugin       \li Case-insensitive
-    \row    \li QImageIOPlugin          \li Case-sensitive
-    \row    \li QMediaServiceProviderPlugin,
-    \row    \li QQmlExtensionPlugin,
-    \row    \li QSensorPluginInterface,
-    \row    \li QScriptExtensionPlugin  \li Case-sensitive
-    \row    \li QSqlDriverPlugin        \li Case-sensitive
-    \row    \li QStylePlugin            \li Case-insensitive
+    The following table summarizes the plugin base classes. Some of the classes
+    are private, and are therefore not documented. You can use them, but there
+    is no compatibility promise with later Qt versions.
 
+    \table
+    \header
+        \li Base Class
+        \li Directory Name
+        \li Qt Module
+        \li Key Case Sensitivity
+    \row
+        \li QAccessibleBridgePlugin
+        \li \c accessiblebridge
+        \li \l{Qt GUI}
+        \li Case Sensitive
+
+    \row
+        \li QImageIOPlugin
+        \li \c imageformats
+        \li \l{Qt GUI}
+        \li Case Sensitive
+    \row
+        \li QPictureFormatPlugin
+        \li \c pictureformats
+        \li \l{Qt GUI}
+        \li Case Sensitive
+    \row
+        \li QAudioSystemPlugin
+        \li \c audio
+        \li \l{Qt Multimedia}
+        \li Case Insensitive
+    \row
+        \li QDeclarativeVideoBackendFactoryInterface
+        \li \c video/declarativevideobackend
+        \li \l{Qt Multimedia}
+        \li Case Insensitive
+    \row
+        \li QGstBufferPoolPlugin
+        \li \c video/bufferpool
+        \li \l{Qt Multimedia}
+        \li Case Insensitive
+    \row
+        \li QMediaPlaylistIOPlugin
+        \li \c playlistformats
+        \li \l{Qt Multimedia}
+        \li Case Insensitive
+    \row
+        \li QMediaResourcePolicyPlugin
+        \li \c resourcepolicy
+        \li \l{Qt Multimedia}
+        \li Case Insensitive
+    \row
+        \li QMediaServiceProviderPlugin
+        \li \c mediaservice
+        \li \l{Qt Multimedia}
+        \li Case Insensitive
+    \row
+        \li QSGVideoNodeFactoryPlugin
+        \li \c video/videonode
+        \li \l{Qt Multimedia}
+        \li Case Insensitive
+    \row
+        \li QBearerEnginePlugin
+        \li \c bearer
+        \li \l{Qt Network}
+        \li Case Sensitive
+    \row
+        \li QPlatformInputContextPlugin
+        \li \c platforminputcontexts
+        \li \l{Qt Platform Abstraction}
+        \li Case Insensitive
+    \row
+        \li QPlatformIntegrationPlugin
+        \li \c platforms
+        \li \l{Qt Platform Abstraction}
+        \li Case Insensitive
+    \row
+       \li QPlatformThemePlugin
+        \li \c platformthemes
+        \li \l{Qt Platform Abstraction}
+        \li Case Insensitive
+    \row
+        \li QGeoPositionInfoSourceFactory
+        \li \c position
+        \li \l{Qt Positioning}
+        \li Case Sensitive
+    \row
+        \li QPlatformPrinterSupportPlugin
+        \li \c printsupport
+        \li \l{Qt Print Support}
+        \li Case Insensitive
+    \row
+        \li QSGContextPlugin
+        \li \c scenegraph
+        \li \l{Qt Quick}
+        \li Case Sensitive
+    \row
+        \li QScriptExtensionPlugin
+        \li \c script
+        \li \l{Qt Script}
+        \li Case Sensitive
+    \row
+        \li QSensorGesturePluginInterface
+        \li \c sensorgestures
+        \li \l{Qt Sensors}
+        \li Case Sensitive
+    \row
+        \li QSensorPluginInterface
+        \li \c sensors
+        \li \l{Qt Sensors}
+        \li Case Sensitive
+    \row
+        \li QSqlDriverPlugin
+        \li \c sqldrivers
+        \li \l{Qt SQL}
+        \li Case Sensitive
+    \row
+        \li QIconEnginePlugin
+        \li \c iconengines
+        \li \l{Qt SVG}
+        \li Case Insensitive
+    \row
+        \li QAccessiblePlugin
+        \li \c accessible
+        \li \l{Qt Widgets}
+        \li Case Sensitive
+    \row
+        \li QStylePlugin
+        \li \c styles
+        \li \l{Qt Widgets}
+        \li Case Insensitive
     \endtable
 
     If you have a new style class called \c MyStyle that you