Remove internal public function from QOpenGLFunctions

QOpenGLContext uses glGetTexLevelParameteriv on desktop OpenGL and so it
got recently added to QOpenGLFunctions as part of the dynamic GL loading
support.

This is unnecessary since such desktop-only code can use the versioned
wrappers (QOpenGLFunction_1_0 for example). In related upcoming changes
in 5.4 the function is removed. This change has to be backported to 5.3
to prevent introducing this public API unnecessarily.

Change-Id: I6fc331091e4e6416e430bf985afcc17a392fc2e3
Reviewed-by: Gunnar Sletta <gunnar.sletta@jollamobile.com>
Restore Qt 4 behavior in default double click handler

Revert 3bb902495291c50a2f06e8e03a62a647db3e5cd4. That fix was an attempt
to handle the issue that has been fixed in 5.3 by
9063edef796ad10eb9ac2229627f36d60168f0e2 and should have been reverted
when the new approach, that restores Qt 4 behavior for widgets, was
introduced.

Task-number: QTBUG-38242
Task-number: QTBUG-36423
Change-Id: I8f8a82da22605fac90543492e9b2cd2b568544e7
Reviewed-by: Jørgen Lind <jorgen.lind@digia.com>
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
When a window loses focus to a popup, event has PopupFocusReason

Followup to debe31e047060d790fb32c06e514d9df476df8bf : a popup
window can have focus, but a QQuickWindow needs to know why
it loses focus when a menu is opened, so that for example
copy/cut/paste Actions can apply to the text which did have
focus before the menu opened.  The event's focus reason provides
enough information to deal with this situation.

Task-number: QTBUG-36292
Task-number: QTBUG-36332
Change-Id: Ifae999a364a61b125a4764c9db204a167bddf0b7
Reviewed-by: Jørgen Lind <jorgen.lind@digia.com>