Doc: use cross-linking to Qt module documentation

Replace links to "\l{http://qt-project.org/doc/"
with links to topic titles. Remove links where QDoc
creates them automatically based on the .index files.
Add the .index files for the modules that are discussed
in the Qt Creator Manual.

Note: the links will only be generated if the Qt used to
build the docs contains the linked modules and documentation
(.index file) has been generated for them.

Change-Id: Ibe624bf3773e7c854c03ebba4db406be0b4a7b90
Reviewed-by: Jerome Pasion <jerome.pasion@digia.com>
Reviewed-by: Eike Ziller <eike.ziller@digia.com>

doc/src/widgets/qtdesigner-app-tutorial.qdoc

@@ -31,8 +31,7 @@
     \title Creating a Qt Widget Based Application
 
     This tutorial describes how to use \QC to create a small Qt application,
-    Text Finder. It is a simplified version of the Qt UI Tools
-    \l{http://qt-project.org/doc/qt-5.0/qtuitools/textfinder.html}{Text Finder
+    Text Finder. It is a simplified version of the Qt UI Tools \l{Text Finder
     example}. The application user interface is constructed from Qt widgets by
     using \QD. The application logic is written in C++ by using the code editor.
 
@@ -198,7 +197,7 @@
     \endlist
 
     For more information about designing forms with \QD, see the
-    \l{http://qt-project.org/doc/qt-5.0/qtdesigner/qtdesigner-manual.html}{Qt Designer Manual}.
+    \l{Qt Designer Manual}.
 
     \section2 Completing the Header File
 
@@ -232,8 +231,7 @@
 
         \li Add code to load a text file using QFile, read it with QTextStream,
             and then display it on \c{textEdit} with
-            \l{http://qt-project.org/doc/qt-5.0/qtwidgets/qtextedit.html#plainText-prop}
-            {setPlainText()}.
+            \l{QTextEdit::setPlainText()}.
             This is illustrated by the following code snippet:
 
             \snippet textfinder/textfinder.cpp 0
@@ -244,9 +242,7 @@
             \snippet textfinder/textfinder.cpp 1
 
         \li For the \c{on_findButton_clicked()} slot, add code to extract the
-            search string and use the
-            \l{http://qt-project.org/doc/qt-5.0/qtwidgets/qtextedit.html#find}{find()}
-            function
+            search string and use the \l{QTextEdit::find()} function
             to look for the search string within the text file. This is
             illustrated by the following code snippet:
 

doc/src/widgets/qtdesigner-overview.qdoc

@@ -35,8 +35,7 @@
 
     \image qtcreator-formedit.png
 
-    For more information about \QD, see the
-    \l{http://qt-project.org/doc/qt-5.0/qtdesigner/qtdesigner-manual.html}{Qt Designer Manual}.
+    For more information about \QD, see the \l{Qt Designer Manual}.
 
     Generally, the integrated \QD contains the same functions as the standalone
     \QD. The following sections describe the differences.

doc/src/widgets/qtdesigner-plugins.qdoc

@@ -41,8 +41,7 @@
     and to change the default plugin path, see \l{How to Create Qt Plugins}.
 
     For more information about how to create plugins for \QD, see
-    \l{http://qt-project.org/doc/qt-5.0/qtdesigner/designer-using-custom-widgets.html}
-    {Using Custom Widgets with Qt Designer}.
+    \l{Using Custom Widgets with Qt Designer}.
 
     \section1 Locating Qt Designer Plugins
 
@@ -75,8 +74,7 @@
     \QC uses its own set of Qt Libraries located in the bundle, and therefore,
     you need to configure the \QD plugins that you want to use with \QC.
     Fore more information about how to deploy applications to Mac OS, see
-    \l{http://qt-project.org/doc/qt-5.0/qtdoc/deployment-mac.html}
-    {Deploying an Application on Mac OS X}.
+    \l{Deploying an Application on Mac OS X}.
 
     The following example illustrates how to configure version 5.2.1 of the
     \l{http://qwt.sourceforge.net/}{Qwt - Qt Widgets for Technical Applications}