Doc: Fix broken \qmlsignal links

Fix the breaks caused by the re-categorizing of \qmlsignal pages

Task-number: QTBUG-35846
Change-Id: I130941b7d13f450a629d6a13a9ec5baa77ddc5e7
Reviewed-by: Jerome Pasion <jerome.pasion@digia.com>
Doc: Changed "WinRT" page title to "Qt for WinRT".

-new title is consistent with other platform pages.

Change-Id: I656d0f5a74d8267971de1cf23e54bd14d0fb2ece
Reviewed-by: Oliver Wolff <oliver.wolff@digia.com>
Reviewed-by: Jerome Pasion <jerome.pasion@digia.com>
Reviewed-by: Andrew Knight <andrew.knight@digia.com>