[Namespaces changes]

edge->edg

clean up of some namespaces to comply the following naming:

Complexes (3 letters namespaces):
order 0 (point cloud    ) :vrt
order 1 (edge meshes)     :edg
order 2 (triangle meshes) :tri
order 3 (triangle meshes) :tet

Simplexes (4 letters namespaces):
order 0 (vertex)      :vert 
order 1 (edge)        :edge 
order 2 (triangle)    :triangle
order 3 (tetrahedron) :tetrahedron

wrap/io_edgemesh/export_svg.h

@@ -61,7 +61,7 @@ first working version
 
 namespace vcg 
 {
-	namespace edge 
+	namespace edg 
 	{
 		namespace io 
 		{