qt5: Fix QAbstractItemModel::createIndex() ambiguity

Signed-off-by: Bartosz Brachaczek <b.brachaczek@gmail.com>
qt5: Port to new QGuiApplication::isSavingSession() function

Signed-off-by: Bartosz Brachaczek <b.brachaczek@gmail.com>
qt5: Port to new QObject::connectNotify() signature

Signed-off-by: Bartosz Brachaczek <b.brachaczek@gmail.com>
qt5: Port QAtomicInt usage

Signed-off-by: Bartosz Brachaczek <b.brachaczek@gmail.com>
qt5: Port to new QAbstractItemView::dataChanged() signature

Signed-off-by: Bartosz Brachaczek <b.brachaczek@gmail.com>
qt5: Port to new QTabletEvent c-tor

Signed-off-by: Bartosz Brachaczek <b.brachaczek@gmail.com>
qt5: Port plugins to Qt5

Signed-off-by: Bartosz Brachaczek <b.brachaczek@gmail.com>
plugin: fix filtering in plugin list

Signed-off-by: Rafał Malinowski <rafal.przemyslaw.malinowski@gmail.com>
plugin: remove unneeded includes

Signed-off-by: Rafał Malinowski <rafal.przemyslaw.malinowski@gmail.com>
gui: fix MessageDialog::show method

Signed-off-by: Rafał Malinowski <rafal.przemyslaw.malinowski@gmail.com>