decorbutton added to libxfcegui4

[Jasper Huijsmans]

Olivier Fourdan wrote:
> Jasper,
> 
> You need to increase the button size in tiny mode.
> 
> Right now, it's 12x12, minus a border of 2 pixels on each side, it
> leaves 8x8 for the decorbutton and it doesn't fit.
> 
> Use 14 as it is in small mode and it's perfect.
> 

In my local tree I increased all button sizes 2 pixels. I think it's 
better. Also from a usability view point - the buttons are rather small 
targets to click.

	Jasper