Strange sizing problems with GridLayout

[Thomas Schüßler <vindolin gmail com>]

Hi everyone,

I'm having a hard time figuring out how the different layout managers 
influence each other when combined.
In this example https://gist.github.com/vindolin/10755038, I would 
expect the blue actor to have a height of 100 pixel but it always gets a 
height equal to the sum of a.width + b.width.

Also I don't really get what the orientation does in a grid layout context.

Am I missing something obvious? :)

Best regards,
Thomas