Set MKL_INTERFACE_LAYER to ILP64 if USE_BLAS64=1 (#3928, #5146)
Patch ARPACK for fortran calling convention to be consistent with MKL.
This patch was obtained from macports: http://trac.macports.org/ticket/35508
Add -ff2c -fno-second-underscore for Fortran code when using MKL and Accelerate
Pass JFFLAGS to ARPACK and openspecfun.