SuiteSparse v5.1.2, Dec 28, 2017.
* improved build process for GraphBLAS
* minor change to CSparse/Lib/Makefile, no change in CSparse version
5.1.1:
* GraphBLAS added to top-level SuiteSparse/Makefile
* GraphBLAS 1.1.1: bug fix to *assign, split AxB for faster compile,
added memory usage statistics, AxB performance improvment
* minor update to [AMD CAMD KLU]/Doc/Makefile's, no change to
version numbers of AMD, CAMD, or KLU