Visualization - Functional Domain management

- Addition of :
* Ressources : DCNSLogo, plus and equal.png.

- Corrections :
* Management of the domain color (considering the domain name);
* Mana. of the domain name width (consider. rectangle domain width).

- Modifications on :
* SVG metamodel : manag. of 'tspan element' (multiples lines) in 'text'
element (reference 'tspans');
* SVG to XML : adding rule to manage 'tspan element'.