QHelpContentModel: Fix that the model sometimes ended up empty

When aborting collecting the content items, sometimes the "abort" state
was not cleaned up correctly, so the next run thought it was aborted
too. If that happened at the end of the multiple start/abort cycles that
happen at initialization, the content model ended up empty.

Task-number: QTCREATORBUG-13233
Change-Id: Ia47a6b033cc3fd1f7a02d5194fb6f7ea68a435c5
Reviewed-by: Christian Kandeler <christian.kandeler@digia.com>
windeployqt: Deploy translation files of the QtWebEngine module.

Task-number: QTBUG-42083
Change-Id: Ibc52780c52399ba13cfa5c501b67bd37ea727d1f
Reviewed-by: Andras Becsi <andras.becsi@digia.com>
New Qt logo

This patch replaces the old Qt logo with the new, flatter one.

The PNGs were optimized via: optipng -o7 -strip "all"

src/assistant/assistant/images/qt-logo.png was deleted since it
is unused.

Task-number: QTBUG-41685
Change-Id: Id04972f87135e15c41d52c5e9f00ad4944d8d1f6
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@theqtcompany.com>
Reviewed-by: Eike Ziller <eike.ziller@theqtcompany.com>
Reviewed-by: Kai Koehne <kai.koehne@theqtcompany.com>
Merge remote-tracking branch 'origin/5.4.0' into 5.4

Change-Id: If7b9ae7b6f77025c775e6b654837b5f041f1aab9
Fix silly taking of address when not intended

We meant to pass the boolean itself, noting whether the property
had changed, not the address of the boolean, cast to a bool.

Found by Clang 3.6:
qlayout_widget.cpp:421:147: warning: address of 'this->m_fieldGrowthPolicyChanged' will always evaluate to 'true' [-Wpointer-bool-conversion]

Change-Id: I8a7db0d0cf02b88043f905333e119a8fb799ea53
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@theqtcompany.com>
Remove unused private members

Found by Clang 3.6:
messageeditorwidgets.cpp:250:14: warning: private field 'm_wrapee' is not used [-Wunused-private-field]
cpp.cpp:309:15: warning: private field 'yyInteger' is not used [-Wunused-private-field]

Change-Id: Ice6aa515123b1ac375816271362772d50b9b8f27
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>
Merge remote-tracking branch 'origin/5.4' into dev

Change-Id: If3345bc6090bac3cddf98c6eed68f47686a3ee75