resolve some compiler warnings with intel c/c++ compiler

* subsurf code had a lot of unused variables, removed these where they are obviously not needed. commented if they could be useful later.
* some variables declorations hide existing variables (many of these left), but fixed some that could cause confusion.
* removed unused vars
* obscure python memory leak with colorband.
* make_sample_tables had a loop running wasnt used.
* if 0'd functions in arithb.c that are not used yet.
* made many functions static

source/blender/python/api2_2x/matrix.c

@@ -774,7 +774,7 @@ static PyObject *Matrix_mul(PyObject * m1, PyObject * m2)
 	return EXPP_ReturnPyObjError(PyExc_TypeError, 
 		"Matrix multiplication: arguments not acceptable for this operation\n");
 }
-PyObject* Matrix_inv(MatrixObject *self)
+static PyObject* Matrix_inv(MatrixObject *self)
 {
 	return Matrix_Invert(self);
 }