Add clearButton-property to QLineEdit.

Based on addAction-API.

Change-Id: Ie6c3d2d728b23a85cdd80428c92ee8208ae0a65c
Done-with: Kevin.Ottens@kdab.com
Reviewed-by: Frederik Gladhorn <frederik.gladhorn@digia.com>
Doc: add winextras to the list of QT variable values

Qt Windows Extras is a new add-on for Qt 5.2.
To make the link work, also added qtwinextras to the
doc configuration file.

Change-Id: Ib7d117908c241812c200ec701b6f2be27fe893c6
Reviewed-by: Jerome Pasion <jerome.pasion@digia.com>
QNX: Enable rendering on different displays using OpenGL

Change-Id: Ife9c090cff732aba42a5cbc04640721e8fdde69d
Reviewed-by: Bernd Weimer <bweimer@blackberry.com>
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>
Doc: Get QDoc to not display the \qtvariable if it is empty.

Change-Id: I5cd2cff23b56180e7bfec7cae84104a16f47fc79
Reviewed-by: Martin Smith <martin.smith@digia.com>