Dialogs: don't allow click passthrough when a dialog is showing

On Android and other non-windowing platforms, clicking outside the
dialog dismisses it if it is non-modal, but if it is modal we still
need to capture the click even though it will not dismiss the dialog.

Task-number: QTBUG-39339
Change-Id: I18e892d1ca9c7ed4bea44c462a84b48ca44915d0
Reviewed-by: Paul Olav Tvete <paul.tvete@digia.com>
FileDialog: handle back and esc keys to reject the dialog

When the dialog was open then pressing the Android back button would
cause it to quit the application as it just went straight through.

Task-number: QTBUG-39204
Change-Id: I69e5f39ab90a5c280ae4dbd1a498fb6f3d4dcf1e
Reviewed-by: Shawn Rutledge <shawn.rutledge@digia.com>
Reviewed-by: Andy Shaw <andy.shaw@digia.com>
Make SliderStyle example use implicitWidth and implicitHeight.

This is what we encourage, so it should be consistent.

Change-Id: I0b9bcaebf45aec599a71a351c924883d432c0af0
Reviewed-by: J-P Nurmi <jpnurmi@digia.com>
Fix TextArea's font

Using a Binding element overrides TextArea::font with a value from
TextAreaStyle::font, whereas the style is only supposed to provide
the default value. Use TextSingleton's font to avoid the original
binding loop.

Task-number: QTBUG-39328
Change-Id: I90113ef03dd31b2a060dfe12361708f99b35eb53
Reviewed-by: Liang Qi <liang.qi@digia.com>
Reviewed-by: Caroline Chao <caroline.chao@digia.com>
TextField::font: fix the default value handling

Assigning undefined to font is not possible, so use TextSingleton::font
as a fallback instead of undefined.

Change-Id: If148f7773ca784c0a1eb78f952dfad073fa9b1e3
Reviewed-by: Liang Qi <liang.qi@digia.com>
Reviewed-by: Caroline Chao <caroline.chao@digia.com>
TableViewColumn: Process all the rows in resizeToContents()

... including the first row.

Task-number: QTBUG-39337
Change-Id: I55bf61168840e9a7a5b31d7be2182b6974371a4a
Reviewed-by: J-P Nurmi <jpnurmi@digia.com>
Merge remote-tracking branch 'origin/stable' into dev

Change-Id: Ife57f59094cb9be9c5e8a187df8d1fd25110a53a