Move the transform and lighting code to two new directories

math:  Provides basic matrix and vector functionality that
               might be useful to multiple software t&l
	       implementations, and is used by core mesa to
	       manage the Model, Project, etc matrices.

	tnl:   The real transform & lighting code from core mesa,
	       including everything from glVertex3f through vertex
	       buffer handling, transformation, clipping, lighting
	       and handoff to a driver for rasterization.

The interfaces of these can be further tightened up, but the basic
splitting up of state and code move is done.

src/mesa/swrast_setup/ss_triangle.c

@@ -29,6 +29,8 @@
 #include "macros.h"
 #include "types.h"
 
+#include "tnl/t_context.h"
+
 #include "ss_triangle.h"
 #include "ss_context.h"