Revert "Fix setVisible() of QWidget has no effect in QTreeWidgetItem"

It introduces  QTBUG-34653 (Qt Designer widget box no longer
repainted after collapsing items or using the filter).

This reverts commit 04de24c6449422d29a0d4760375aa94f59222fa3.

Task-number: QTBUG-13522
Task-number: QTBUG-34653
Change-Id: Ieb9766e7f15acea901fce4ad7142aa72557b9957
Reviewed-by: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>
Fix QVariant::canConvert with longlong

Add few cases where conversion to or from LongLong was missing

We need to make it work if we want to use variant.canConvert<qint64>

[ChangeLog][QtCore][QVariant] Fixed QVariant::canConvert with longlong

Change-Id: I0f65073802b62d99250601dd90a8cd2e4d934b60
Reviewed-by: Jędrzej Nowacki <jedrzej.nowacki@digia.com>
QVariant: Convert automatically from enum types to integral types.

[ChangeLog][QtCore][QVariant] Variant containing enum types can now
be converted to integer

Change-Id: Ibbbc9ae29ab45d67c582fa2d406afc19c5dc41ce
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Jędrzej Nowacki <jedrzej.nowacki@digia.com>
Prevent clang from warning about unused variables

Fixes a compiler warning introduced by 79b975756a100cc46182

Change-Id: Ie9bc677d061f0bb0530eae88715069042b2ab440
Reviewed-by: hjk <hjk121@nokiamail.com>
Reviewed-by: Shawn Rutledge <shawn.rutledge@digia.com>
Doc: Added some Qt Quick examples to manifest-meta.qdocconf

Change-Id: Ie199b48faf885d9a50b7dfd8a73cc99e69998102
Reviewed-by: Jerome Pasion <jerome.pasion@digia.com>
Reviewed-by: Topi Reiniö <topi.reinio@digia.com>
Doc: Move threading overviews from qtbase.git to qtdoc.git

- This topic is  relevant to multiple modules, as illustrated by the
  "Thread-Support in Qt Modules" page. Multithreading can be done in
  both C++ and QML.
- Moving also fixes links to QML-related pages.
- Snippets are copied, not moved. QThreadStorage docs need them.
- QDoc: "DEPENDS += qtdoc" added to keep the "\reentrant" command
  working. It creates a link to the "reentrant" keyword.

Change-Id: I2cdf6139e62d66911561c30fcca7aab160a694b1
Reviewed-by: Jerome Pasion <jerome.pasion@digia.com>
Fix QFileDialog::getSaveFilename() with a given default name

The QFileDialogOptions::initiallySelectedFiles were overridden, and
the given filename was also not properly converted to a local file URL.

Task-number: QTBUG-34408
Task-number: QTBUG-34446
Change-Id: I51d05b954a5393d10db9232945ba05bda7068e73
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Remove disused version of QPlatformMessageDialogHelper::clicked signal

It has been replaced with a version that sends both the button and
the role.

Change-Id: I47156288bf2039cfdfd4cf09f75563347bfb4141
Reviewed-by: BogDan Vatra <bogdan@kde.org>