MacPorts' lapack is not guaranteed to produce libblas.dylib. For example if the +openblas variant is used, then lapack uses openblas.
This commit tries to find and use libopenblas.dylib if libblas.dylib is not found.
Fixes usage of BLAS_ROOT
The BLAS and LAPACK implementations that come with the Accelerate Framework (soft-linked in /usr/bin) caused a random crash when exiting the program, only if the variable ENABDS was set. This bug disappears when linking to the libraries that Homebrew or Macports install, or when manually downloaded, built and installed by the user