Doc: Fix module name format

Follow the conventions at
http://qt-project.org/wiki/Spelling_Module_Names_in_Qt_Documentation



QtCore         -> Qt Core
QtDBus         -> Qt D-Bus
QtDesigner     -> Qt Designer
QtGui          -> Qt GUI
QtImageFormats -> Qt Image Formats
QtNetwork      -> Qt Network
QtPrintSupport -> Qt Print Support
QtScript       -> Qt Script
QtSql          -> Qt SQL
QtSvg          -> Qt SVG
QtTest         -> Qt Test
QtWebKit       -> Qt WebKit
QtWidgets      -> Qt Widgets
QtXml          -> Qt XML

QtConcurrent   -> Qt Concurrent (partial)
QtQuick        -> Qt Quick      (partial)

Also, distinguish between "module" and "library"

Change-Id: Icb8aa695ae60b0e45920b0c8fce4dc763a12b0cd
Reviewed-by: Jerome Pasion <jerome.pasion@digia.com>