The default value overwrites the value set in the parent constructor 
(Javascript...). Therefore the value needs to be intialized explicitly 
after the parent constructor has run.

#659

The index was one off, when looking up the correct child element.

Only background color makes sense here.

#669

The icon 'table' does look different for some reason. Taking the second 
best available icon.

MeasurePipe is now standalone.

20s is hopefully enough.

Expansion oanel seems not to render properly -  the last element is not 
there right away. A wait-command seems to help.

Remove button is permanently visible and bith buttons are now in the 
lower left corner

This feature is incomplete. Button is hidden until it's done.