Doc: Mark the remaining C++ API \internal

- Hide the C++ classes entry from the help file (.qdocconf)
- Remove link to the C++ classes from the module front page
- Mark classes and namespace \internal
- Mark the C++ module page \internal

Change-Id: I07b04af84b45d048c5cbb133bd5d70f8b38f25dd
Reviewed-by: Topi Reiniö <topi.reinio@theqtcompany.com>

src/virtualkeyboard/doc/qtvirtualkeyboard.qdocconf

@@ -29,12 +29,12 @@ qhp.QtVirtualKeyboard.filterAttributes                  = qtvirtualkeyboard $QT_
 qhp.QtVirtualKeyboard.customFilters.Qt.name             = QtVirtualKeyboard $QT_VERSION
 qhp.QtVirtualKeyboard.customFilters.Qt.filterAttributes = qtvirtualkeyboard $QT_VERSION
 
-qhp.QtVirtualKeyboard.subprojects = classes qmltypes examples
+qhp.QtVirtualKeyboard.subprojects = qmltypes examples # classes
 
-qhp.QtVirtualKeyboard.subprojects.classes.title = C++ Classes
-qhp.QtVirtualKeyboard.subprojects.classes.indexTitle = Qt Virtual Keyboard C++ Classes
-qhp.QtVirtualKeyboard.subprojects.classes.selectors = class
-qhp.QtVirtualKeyboard.subprojects.classes.sortPages = true
+# qhp.QtVirtualKeyboard.subprojects.classes.title = C++ Classes
+# qhp.QtVirtualKeyboard.subprojects.classes.indexTitle = Qt Virtual Keyboard C++ Classes
+# qhp.QtVirtualKeyboard.subprojects.classes.selectors = class
+# qhp.QtVirtualKeyboard.subprojects.classes.sortPages = true
 
 qhp.QtVirtualKeyboard.subprojects.qmltypes.title      = QML Types
 qhp.QtVirtualKeyboard.subprojects.qmltypes.indexTitle = Qt Virtual Keyboard QML Types
@@ -48,4 +48,4 @@ qhp.QtVirtualKeyboard.subprojects.examples.sortPages = true
 
 navigation.landingpage = "Qt Virtual Keyboard"
 navigation.qmltypespage = "Qt Virtual Keyboard QML Types"
-navigation.cppclassespage = "Qt Virtual Keyboard C++ Classes"
+# navigation.cppclassespage = "Qt Virtual Keyboard C++ Classes"

src/virtualkeyboard/doc/src/qtvirtualkeyboard-index.qdoc

@@ -102,7 +102,6 @@
 
     \list
         \li \l{Qt Virtual Keyboard QML Types}{QML Types}
-        \li \l{Qt Virtual Keyboard C++ Classes}{C++ Classes}
     \endlist
 
     \section1 Examples

src/virtualkeyboard/doc/src/qtvirtualkeyboard-module-cpp.qdoc

@@ -30,7 +30,8 @@
     \title Qt Virtual Keyboard C++ Classes
     \brief Provides classes to implement input methods for virtual keyboards.
 
-    \ingroup modules
+    \internal
+
     \qtvariable virtualkeyboard
 
     To include the definitions of the module's classes, use the following directive:

src/virtualkeyboard/inputcontext.cpp

@@ -58,6 +58,7 @@ QT_END_NAMESPACE
     \inmodule QtVirtualKeyboard
 
     \brief Namespace for the Qt Virtual Keyboard C++ API.
+    \internal
 */
 
 namespace QtVirtualKeyboard {
@@ -146,6 +147,7 @@ Q_DECLARE_OPERATORS_FOR_FLAGS(InputContextPrivate::StateFlags)
     \class QtVirtualKeyboard::InputContext
     \inmodule QtVirtualKeyboard
     \brief Provides access to an input context.
+    \internal
 */
 
 /*!

src/virtualkeyboard/inputengine.cpp

@@ -135,6 +135,8 @@ private:
     \brief The InputEngine class provides an input engine
     that supports C++ and QML integration.
 
+    \internal
+
     The input engine is responsible for routing input events to input
     methods. The actual input logic is implemented by the input methods.
 

src/virtualkeyboard/selectionlistmodel.cpp

@@ -87,6 +87,8 @@ public:
 
     \brief List model for selection lists.
 
+    \internal
+
     This class acts as a bridge between the UI and the
     input method that provides the data for selection
     lists.

src/virtualkeyboard/shifthandler.cpp

@@ -76,6 +76,8 @@ public:
     \class QtVirtualKeyboard::ShiftHandler
     \inmodule QtVirtualKeyboard
     \brief Manages the shift state.
+
+    \internal
 */
 
 ShiftHandler::ShiftHandler(InputContext *parent) :