Fix: Initialize all needed member vars

Change-Id: I74b71d93e25e4b3b0c1a5766f2fbc4f71aebecbb
Reviewed-by: Gunnar Sletta <gunnar.sletta@jollamobile.com>
Increase tolerance for warning about QTest::qSleep() for Windows.

50% is too strict, it clutters the logs.

Change-Id: Ib391064f32e39a1192e77d872cd99b7f95a5065a
Reviewed-by: Ulf Hermann <ulf.hermann@digia.com>
Improve handling of temporary directories in SQL tests.

Initialize directory delayed in shared code and add checks to verify
that it is valid. Close attached / cloned databases to prevent locks
on files and leaking temporary directories caused by SQLite:

QTemporaryDir: Unable to remove "...\Temp\tst_qsqldatabase-P1XkOA" most likely due to the presence of read-only files.
QTemporaryDir: Unable to remove "...\Temp\tst_qsqltablemodel-P1XkOA" most likely due to the presence of read-only files.
QWARN  : tst_QSql::concurrentAccess() QTemporaryDir: Unable to remove "...\Temp\tst_qsql-l0VAKJ" most likely due to the presence of read-only files.

Change-Id: If85bbaed04bb1a32e427d642be332996d967f796
Reviewed-by: Andy Shaw <andy.shaw@digia.com>
Reviewed-by: Joerg Bornemann <joerg.bornemann@digia.com>
Make it possible to render QtWebEngine in QOpenGLWidget

Setup the GL context as shared with the Qt global share context.

Change-Id: I199cfc7d290466d0ad99294bcffcd738b615862b
Reviewed-by: Laszlo Agocs <laszlo.agocs@digia.com>