Doc: Import statement takes version info only from /inqmlmodule

This means that when changing from for example 1.0 to 1.1 you need to update the doc of every types in that class. (That's a lot of them in qtdeclarative or qtquickcontrols)

It would be convenient to have the module version specified in only one place.

Ffor info the pro file of the qml imports contains a IMPORT_VERSION tag if that could help. Otherwise maybe using the version given in \qmlmodule could be used.

For the moment we have for a module:

    \qmlmodule QtQuick.Controls 1.1
    \title Qt Quick Controls QML Types
    \ingroup qmlmodules
    \brief Provides QML types for user interfaces.

And an item in that module:

    \qmltype Button
    \inqmlmodule QtQuick.Controls 1.0
    \since QtQuick.Controls 1.0
    \ingroup controls
    \brief A push button with a text label.

If you want Button to have the import statement "import QtQuick.Controls 1.1" in the doc, you need to change " \inqmlmodule QtQuick.Controls 1.1"

When using:

• \inqmlmodule QtQuick.Controls
• \inqmlmodule QtQuick.Controls 1
• \inqmlmodule QtQuick.Controls 2
  The version set in \qmlmodule is ignored and version is 1.0 or 2.0 for the last case.
  Default major and minor versions are 1 and 0 in qtbase/src/tools/qdoc/node.cpp