Material preset "Metal" for extruded custom shapes

[Regina Henschel]

Hi Miklos, hi all,

I have discussed the problem with the OASIS TC today. Their advise is, 
to not use Boolean as data type but a string and have namespaced values. 
That way it is more flexible in allowing further different ways to 
implement a 'metal' rendering.
So I will change that.

The attribute itself will be with prefix 'loext' till it is integrated 
in ODF. But what namespace prefix (and associated namespace) should I 
use for the value? I think, a meaningful prefix would be "loext" or 
"drawooo".

And a second question is the data type of the internal (and API) 
property. In the current state of the patch it is "MetalColored" with 
data type Boolean.

Kind regards,
Regina