missing else

We are checking the whole prototype chain now

Reviewed-by: Thomas Hartmann

Do not use scaled on null pixmaps

While editing BorderImage margins I do not allow
negative margins anymore.

The label shows the zoom factor and there is also a
slider now.

A tooltip is now shown while editing BorderImage
margins.

Instead of the "Disable permanently" action, I added
a checkable action "Show depending on context".

If the Quick Toolbar is forced by a shortcut it can
be enabled now.

As in 479bcbd5

Pinning is now indicated by a different icon and you can press the
modified button to unpin the toolbar. This way pinning is way more
discoverable and easier to understand.

Using more *::Constants::ICON_* where it makes sense and
wrapping the file names into QLatin1String where they were
missing.

The increased usage of the ICON constants needed a few more
cross plugin includes of *constants.h, here and there.
I think that it is OK, since the dependencies were alredy there
icon resource wise.

There is now a nice preview for images and the
properties and borders of a BorderImage can
be visually edited

BugReport: QTCREATORBUG-1959

Proper absolute positioning is now possible

The scope is always needed

Image.PreserveAspectCrop not PreserveAspectCrop
The scope is needed

To many signals were emitted which lead to unneccary
rewriting.

Eat events to avoid moving the (parent) pane

if there is no place for the property pane we hide it