[Cairo] New functions for cairo_matrix

[Carl Worth]

On Nov 14, Duncan Mak wrote:
 > int
 > cairo_matrix_equals (const cairo_matrix_t *x, const cairo_matrix_t *y)

This function looks fine. 

 > cairo_status_t
 > cairo_matrix_get_element (const cairo_matrix_t *matrix, int i, int j, 
 > double *element)

There's nothing here that can't already be done by
cairo_matrix_get_affine is there?

-Carl