hypre: remove "--with-examples" flag

Examples are unaffected by flag settings for main makefile.
hypre: reorganize tests

Reorganize tests and execute C-based executables.
hypre: add "--with-openblas" flag
hypre: build with sys BLAS, add "--without-blas"
hypre: "without-blas" -> "without-accelerate"
hypre: streamline BLAS logic