Cycles / Wireframe node:
* Added a wireframe node (Input category) to get access to Mesh wireframe data. 
The thickness can be controlled via a "Size" parameter, and is available in world units (default) and screen pixel size. 
* Only the triangulated mesh is available now, quads is for later. 

Documentation:
http://wiki.blender.org/index.php/Doc:2.6/Manual/Render/Cycles/Nodes/More#Wireframe

Render and Example file:
http://www.pasteall.org/pic/show.php?id=51731
http://www.pasteall.org/blend/21510

git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@56928 954f8c5b-7b00-dc11-b283-0030488c597c